Wednesday, 6 July 2022

"Passive House" Standards

“Passive House” is today’s most energy efficient building standard. Buildings that meet the Passive House standard use 90% less energy for heating and cooling than traditional homes while being far more comfortable and healthier. A Passive House conserves energy by creating a nearly air-tight, super insulated building envelope that uses the sun and ambient heat to achieve a comfortable indoor environment. A ventilation system including what is called a heat recovery ventilator or HRV is used to provide a continuous supply of clean fresh air. Heat collected by the HRV is pumped back into the home in winter, keeping you warm, or pumped out in Summer, keeping you cool. Passive House Standards offer three huge benefits.

  1. Increased Personal Health & Comfort
  2. Energy Efficiency
  3. Long Term Value

What if you never had to turn on the heat or AC in your home again? How much would you save on heating and cooling costs throughout the year? Probably quite a bit. The Department of Energy estimates that heat and air conditioning makes up almost half of the average household’s energy bills. That’s why homes built to Passive House Standards are such a great value. Imagine cutting your energy bills by as much as 90% each money. All with increased air quality and comfort.

Passive Homes use a combination of ultra-high levels of fabric insulation, airtight building envelopes, and passive heating and cooling techniques to keep spaces ventilated and comfortable all year long. In many cases, passive homeowners require absolutely no backup heating or cooling systems. Thanks to the International Passive House Association’s rigid standards for housing design.

Passive House Design Overview

SOLAR ORIENTATION

Passive House designers use detailed annual weather data to model a building’s energy performance. The building’s shape is a balance of both form and function. Minimizing heat loss through the exterior is a top design goal which results in an efficient design. Window sizes and orientation are optimized for energy balance throughout the year. A well balanced passive solar design adds excellent day lighting throughout the interior. Sunlight is an excellent source of heat in a Passive House. Heat from the sun is kept in the house by the HRV instead of released to the outdoors like in a traditional home.

HIGH INSULATION

Passive House buildings are super insulated. With walls two to three times as thick as today’s standard construction. This creates a stable and predictable indoor temperature without the need for constant heating or cooling adjustments. Because a steady temperature is far more comfortable than a fluctuating one. And with a Passive House you don’t have drafts and cold / hot spots like in a standard home.

Walls are designed to allow for proper moisture management that results in a long lasting and exceptionally healthy building. Homes built to Passive House Standards also repel mold and mildew growth much better than traditional homes.

HIGH PERFORMANCE WINDOWS AND DOORS

Windows and doors are weak links in a building’s thermal defense system. We can all relate to cold drafts in an average home. What most people don’t realize is air travels both ways through a crack in the exterior. In winter your not only letting cold air in but warm air is also seeping out.Just the opposite is happening in summer. Your AC is cooling the outdoors while hot air seeps in. Both of these situations are very costly and inefficient.

Passive House design places significant emphasis on installing high performance windows and exterior doors. To meet the needs of various climate zones, windows must meet strict standards regarding insulation, air tightness, and solar heat gain values. Exterior glazing is generally triple pane glass on a Passive House. This is a huge upgrade from the double or single pane glass used on a standard home.

AIR TIGHT ENCLOSURE

Passive House takes great care in designing, constructing and testing the building for a near air tight envelope. Blower door testing is a mandatory technique in assuring high building performance through a virtually leak free enclosure. Walls are carefully designed to be virtually air tight. This helps greatly in keeping a constant temperature inside the home with minimal effort.

AIR VENTILATION WITH HEAT RECOVERY HRV

The heat recovery ventilator, provides a constant supply of filtered, fresh, outdoor air while pumping out old, stale, indoor air. Inside the HRV, heat from outgoing stale air is transferred to the incoming fresh air, while it’s being filtered. This process provides continuous comfort and a huge upgrade in indoor air quality.

Thermal Bridge Free Construction

Thermal bridging occurs when a poorly insulated material allows an easy pathway for heat flow across a thermal barrier. The most common form in a traditional home are the exterior wall studs and ceiling rafters. Any component in a building assembly that “bridges” inside and outside thermally, allowing heat and cool to short circuit the thermal resistance built into that building assembly, is considered a thermal bridge. They hide in plain sight: in the form of wood framing, or a junction between wall and concrete foundation, a balcony slab, or even a single metal tie penetrating a wall.  In each case they interrupt the insulation layer with a material that conducts heat, providing a direct line for the transfer of thermal energy across the building envelope. Buildings without many thermal bridges is considered thermal bridge free construction.

 

What Classifies a Building as a Passive House?

Passive House is the world‘s leading standard in energy efficient construction.

The Passive House Standard stands for quality, comfort and energy efficiency. Passive Houses require very little energy to achieve a comfortable temperature year round, making conventional heating and air conditioning systems obsolete. While delivering superior levels of comfort and air quality. While homes built to Passive House Standards can use different techniques to achieve their goals, they all have to meet the same standards. Generally these standards fall into five primary requirements:

  1. The Space Heating Energy Demand is not to exceed 15 kWh per square meter of net living space (treated floor area) per year or 10 W per square meter peak demand.
  2. In climates where active cooling is needed, the Space Cooling Energy Demand requirement roughly matches the heat demand requirements above, with an additional allowance for de-humidification.
  3. The Renewable Renewable Primary Energy Demand (PER, according to PHI method), the total energy to be used for all domestic applications (heating, hot water and domestic electricity) must not exceed 60 kWh per square meter of treated floor area per year for Passive House Classic.
  4. In terms of Airtightness, a maximum of 0.6 air changes per hour at 50 Pascals pressure (ACH50), as verified with an onsite pressure test (in both pressurized and depressurized states).
  5. Thermal comfort must be met for all living areas during winter as well as in summer. All parts of the home must stay below 25 degrees Celsius at least 90 percent of the time.

Passive House buildings are designed and verified with the Passive House Planning Package (PHPP)

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These are what iPHA considers the “hard requirements” for Passive House certification. There are also a number of additional “soft” requirements that offer more specific objectives for how to achieve the broader energy goals. Such as how to design the building envelope and the types of windows and doors that allow the house to meet the association’s guidelines. To review these standards in detail, you can go to the Passive House Resource Center and read each specific requirement.

5 Passive House Principles

All of the above criteria are achieved through design and implementation of the 5 Passive House principles. Thermal bridge free design, superior windows, ventilation with heat recovery, quality insulation and airtight construction.


The following five basic principles apply for the construction of Passive Houses:

  1. Thermal insulation
    All opaque building components of the exterior envelope of the house must be very well-insulated. For most cool-termperate climates, this means a heat transfer coefficient (U-value) of 0.15 W/(m²K) at the most, i.e. a maximum of 0.15 watts per degree of temperature difference and per square metre of exterior surface are lost.
  2. Passive House windows
    The window frames must be well insulated and fitted with low-e glazings filled with argon or krypton to prevent heat transfer. For most cool-termperate climates, this means a U-value of 0.80 W/(m²K) or less, with g-values around 50% (g-value= total solar transmittance, proportion of the solar energy available for the room).
  3. Ventilation heat recovery
    Efficient heat recovery ventilation is key, allowing for a good indoor air quality and saving energy. In Passive House, at least 75% of the heat from the exhaust air is transferred to the fresh air again by means of a heat exchanger.
  4. Airtightness of the building
    Uncontrolled leakage through gaps must be smaller than 0.6 of the total house volume per hour during a pressure test at 50 Pascal (both pressurised and depressurised).
  5. Absence of thermal bridges
    All edges, corners, connections and penetrations must be planned and executed with great care, so that thermal bridges can be avoided. Thermal bridges which cannot be avoided must be minimised as far as possible.

 

Multi Use

Passive building principles can be applied to almost all building types. From single family homes to multifamily apartment buildings, offices, and skyscrapers. 

Passive design strategy carefully models and balances a comprehensive set of factors including heat emissions from appliances and occupants to keep the building at comfortable and consistent indoor temperatures.  As a result, passive buildings offer tremendous long term benefits in addition to energy efficiency.

  • Higher insulation levels and airtight construction provide unmatched comfort even in extreme weather conditions.
  • Continuous mechanical ventilation of fresh filtered air provides superior indoor air quality
  • A comprehensive systems approach to design and construction produces extremely resilient buildings. 
  • Passive buildings offer the best path to Net Zero and Net Positive by minimizing the load renewables are asked to provide. 

Can An Existing Building Meet Passive House Standards?

The Passive House Standard cannot always be achieved in building renovations at a reasonable cost.This is due, for example, to unavoidable thermal bridges through existing basement walls. The Passive House Institute has developed the EnerPHit standard for such buildings.

The EnerPHit seal provides the certainty that an optimum thermal protection standard has been implemented for the respective existing building. Through the use of Passive House components, EnerPHit certified buildings offer nearly all the advantages of a Passive House building to the residents, while at the same time offering optimum cost-effectiveness.

An EnerPHit retrofit includes the insulation of the floor, exterior walls and roof with Passive House insulation thicknesses, installing Passive House windows and reducing air leaks. A ventilation system with heat recovery ensures reliable fresh air. Thermal bridges are reduced to a reasonable extent.

What Is the Difference Between Passive House Certification and LEED?

LEED certification, one of the more common green home labeling standards used in the US, rates sites across multiple measurements. These include not only the air quality and energy efficiency, but also the sustainability of the materials and how properties encourage greener behaviors. Such as recycling or biking to work. Passive homes, on the other hand, focus almost entirely on how efficiently the home maintains comfortable temperatures. Because the Passive House Institute is based in Germany, it’s much more common to find homes rated with this certification in Europe than in the US.

How Can I Convert My Home into a Passive House or Build a New Passive House?

If you’re really sold on the idea of passive homes, your first step should be to contact a New Home Builder like Gambrick, if your in NJ that is. If not then find a top local builder who has experience building custom homes, dealing with LEED certification or is familiar with Passive House building techniques and principles.

Some building sites have suggested that a passive house retrofit may only be worth it for a wealthy homeowner with a serious investment in green building. That’s because, in some cases, the airtight requirement may mean renovating the existing walls and foundation. Essentially rebuilding your home from the ground up. You may see some more effective (and budget-friendly) results by simply implementing some features from the Passive House tool belt, such as airtight window assemblies with Low-E glazing; roofing overhangs, awnings and shades for passive cooling; or a thermal mass wall to help with both your heating and cooling needs.

To answer all these questions you should schedule a consultation with a qualified home builder or Passive House designer.

Heat Pumps

For Commercial, Industrial and substantial private properties installations

With the ever rising costs of gas, oil and electricity, with attendant heating, hot water and cooling needs - now is the right time to consider Heat Pumps [at long last - when we consider that Sweden has been installing heat pumps for over 60 years - heck I remember learning about them on my Construction Degree in 1972! However there are several vital prerequisites that need to be in place - otherwise the electricity costs can spiral out of control - see later]

  • · Heat pumps for industrial and commercial use
  • · Heating power from 50 kW to 1000 kW (and more)
  • · Working fluid: R134a (alternative R407C)**
  • · Multistage options
  • · Bespoke according to your demand

*Can be powered by an ORC [Organic Rankine Cycle] THE RANKINE CYCLE The Rankine Cycle is a thermodynamic cycle that converts heat into work. The heat is supplied to a closed loop, which typically uses water as working fluid. The Rankine Cycle based on water provides approximately 85% of worldwide electricity production. The Organic Rankine Cycle's principle is based on a turbogenerator working as a conventional steam turbine to transform thermal energy into mechanical energy and finally into electric energy through an electrical generator. Instead of generating steam from water, the ORC system vaporizes an organic fluid, characterized by a molecular mass higher than that of water, which leads to a slower rotation of the turbine, lower pressures and no erosion of the metal parts and blades.

** A growing focus on the environmental impact of refrigerants is fuelling demand for refrigeration solutions that can provide satisfactory cooling performance with a lower impact on global warming. This is propelling environmentally friendly refrigeration solutions to the top of the corporate sustainability agenda. In addition, local legislation is increasingly targeting refrigerant gases with high Global Warming Potential (GWP). R134a and R407c

Our SUSTAINABLE Designs for bespoke Heating & Cooling systems, with possible Electricity Micro Generation

More than 45 years of experience with one of the leaders in the utilization of geothermal energy. Bespoke and efficient heat pumps solutions are our strength, energy savings and energy efficiency are our goals - along with saving money on bills! Renewable energy directly supplied from the ground beneath a building is one of the most sustainable ways of long-term energy usage. As a seasonal "buffer" - to smooth out the peaks and troughs of supply and demand.

The earth is a huge energy storage system, which permanently regenerates through solar radiation. Every square metre of our earth receives a quantity of 750–1,100 kWh of solar energy yearly. Due to this amount of heat, constant temperature levels averaging 10 to 12° Celsius prevail all over the year in Central Europe in the earth from a depth of approximately 10 metres, and this temperature rises by 1° Celsius per each 33 metre of depth. It is quite simple and very cost-efficient to use the heat stored within the ground for heating purposes. About 80% of the required heating energy can be extracted from the ground by means of HEAT PUMPS, the remaining 20% we use, in form of electric power, for operation of the heat pump. However, with the rising popularity on micro generation [of electricity] even that aspect can be reduced to zero running costs.

As a result of heat extraction during winter, the temperatures of the ground decrease. Due to this much-appreciated side effect, the ground may virtually be used for free for cooling purposes during summer. It's simply a gigantic "battery", a buffer, as it were to reduce peak demand

WHAT WE DO?

Irrespective of the size of the project, our focus is always set on the design and implementation of an efficient and energy-saving heat pump solution. A perfect heat pump solution is the result of early stage expert consultation provided to the client combined with the compilation of all essential data regarding climate, soil conditions [on larger projects a soil survey may well be beneficial, water table, building [assuming extremely well insulated building 'fabric' - or upgrading to such - is a VITAL prerequisite] and occupancy dynamics and requirements. This data is essential in order to produce a viable heat pump solution as well as the results of the simulation calculations we use to determine the economically usable energy supply of the earth.

By careful calculation and selection of heat pump components - from heat-exchangers, compressors, buffer storage, expansion valves and circulation pumps – we can provide significant savings on initial capital costs and annual operating costs. In addition supplementing the electrical needs by generation via PV Solar and/or Vertical Axis Wind Turbines or Even Micro Hydro if appropriate.

Factors to consider with existing or new properties, 

  • we cannot stress enough the importance of significant INSULATION of the fabric of the building to maintain comfort levels
  • This may also need to be combines with a mechanical-ventilation system with heat recovery.
  • Heat Pumps are best suited to underfloor heating systems, it is impractical to consider them for a radiator based systems
  • See Passive House Standards

Due to our considerable experience and confidence in our systems we can offer extended warranty periods.

The same rules apply: experience is everything. The concept – is actually simple – does however quite often lead to unsatisfactory results if the overall design and the simulation are not made by experienced specialists. Heat pumps that are designed without adequate experience, are frequently oversized and consequently inefficient. Our clients will however profit by our decades of experience in the implementation of efficient and economic projects.

Contact Us for a Survey of your Premises or Project

Heat pumps - heat from nature

Heat pumps are the first choice for those who want to lower their heating bills and generate heat in a more environmentally responsible way. After all, the environment provides the heat pump with an unlimited and free supply of the energy it needs. This fully-fledged heating system needs very little power for its drives and pumps in order to make this energy available within the premises. A heat pump makes you independent of fossil fuels, or can replace them, and in addition, actively contributes towards reducing CO2 emissions.

Simple principle, great result

A heat pump works in an analogous way to a refrigerator – simply the other way around.

In a 'fridge, heat is transferred from the inside to the outside. With a heat pump, this happens the other way around. Heat from the air or the ground is transferred into the living space via the heat pump system. Vapour from a refrigerant is compressed to increase the temperature, to make it high enough for central heating and direct hot water [DHW] heating. in summer in reverse the heat pump can cool - which is of much greater importance in Southern UK and much more so in Southern Europe - [see the irradiation maps]


Renewable energy from ambient heat

Heat pumps use ambient heat from the water, ground or air. This ambient heat is in practice, "stored" solar energy or geothermal heat from below ground. Ambient heat is therefore a renewable energy, of which we have an inexhaustible supply.
Unlike fossil fuels, renewable energies have the big advantage of being able to be regenerated. In addition, ambient heat is a decentralised energy supply, which is always available and which can be used without the need for complex supply systems or centralised energy infrastructures.

Use with various energy sources

The best heat source for each individual case depends on local conditions and the actual heat demand. Heat pumps can use various energy sources:

  • Air – practically unlimited availability; lowest investment costs, but least efficient
  • Ground – via geothermal collector, geothermal probe or ice store; very efficient
  • Water – extremely efficient; observe water quality and quantity
  • Waste heat – subject to availability, volume and temperature level of the waste heat

Advantages of heat pumps

60 to 75% lower heating costs

Heat pumps obtain 3/4 of required energy free of any charge, from the environment in which you live. Soil, groundwater, and outside air store huge amounts of thermal energy which can be transformed into heating energy using heat pumps. The savings are considerable compared to other conventional heating systems. The amount of power consumed by heat pumps is notably lower than the amount of heat they generate. 

Smart future investment


If you decide to install a heat pump today, you should be aware you are making an investment for the future. Its true value lies in many measurable and non-measurable aspects. In addition to the safety of investment, flexibility, low heating costs, comfort, and many economic and ecological benefits, a heat pump is an investment in your future and the future of your children.

New building, refurbishment, or heating system replacement

A heat pump is an ideal solution for heating and cooling of newly constructed or refurbished buildings, or when replacing an existing heating system or even simply an older boiler - it may even be feasible to retain the internal distribution. Since it operates on the principles of low-temperature heating, it is suitable for both underfloor heating and heating with wall-mounted radiators, as well as a combination of both. Heat pumps are also appropriate for rebuilt or refurbished buildings with radiator heating since new high temperature heat pumps can reach water temperatures of 80°C.

Warm in the winter, cool in the summer

Unique heat pump technology allows your heating system to heat your home during the winter and cool it during the summer without additional work or investment. The heat pump system can be used for cooling regardless of whether you use fan coils or underfloor heating.

Contact Us for a Survey of your Premises or Project

 

 


Saturday, 27 February 2021

Pumped Storage - A 'Battery' of sorts

 The Principles of Pumped Storage


Pumped storage hydro-electricity works on an extremely simple principle.

Two reservoirs at different altitudes are necessary. When the water is released, from the upper reservoir under gravity, energy is created by the downflow which is directed through high-pressure shafts, linked to turbines.

In turn, the turbines power the generators to create electricity.

Water is pumped back to the upper reservoir by linking a pump shaft to the turbine shaft, using an electric motor to drive the pump.

The pump motors are powered by electricity from the National Grid - the process usually takes place overnight when national electricity demand is at its lowest

A dynamic response - In the example of Dinorwig's six generating units, they can achieve maximum output, from zero, within 16 seconds.

Pump storage generation offers a critical back-up facility during periods of excessive demand on the national grid system.

In effect this pumped storage system is a form of demand management, in short a "battery" of stored potential energy.

Dinorwig and Ffestiniog supply electricity to the Grid on a daily basis, as well as providing back-up for periods of heavy demand. The stations offer fast response times - in the case of Dinorwig, probably the fastest of any power facility in the world - 1,728MW from standstill n just 90 seconds.

Each of Dinorwig's six generating units can produce 288MW of electricity, offering a combined station output of 1728MW. Ffestiniog's four 90MW units have a combined generating capacity of 360MW.

About Dinorwig Pumped Storeage, Snowdonia, Wales

The project was begun in 1970 with an environmental and economic appraisal of three sites, which seemed to offer the right conditions. In 1972 Dinorwig was chosen largely on environmental grounds (the area is already extensively altered by man – the Slate quarries – and attracts thousands of visitors, so can't be said to be wild: the other two sites were much less industrialised), and in 1973 the Act permitting Dinorwig to be built was passed. Exploratory tunnels and bypasses constructed, but the main civil engineering contract was not let until December 1975 and started in January 1976. It was the largest civil contract in Europe at the time (probably now overtaken by projects such as the Channel Tunnel).
Lower Dinorwig Reservior


Over the next 6 years the civil construction was continued, the mechanical engineering (putting in the Machines) and the electrical side (all the transmission gear, switching etc.) being started as and when. Areas of excavation and building allowed. The first generation was in 1982; the scheme was in full production and officially opened in 1984.

The workforce peaked at 2,700 of which 90% were local. The agreed figure had been 70%. So no work camps were necessary, most living at home; this reduced labour relations difficulties both with the local communities, and the strife within camps, which sometimes exists when people work and live too closely, without the usual outlets.

Since so much local labour was used, training was necessary. As work progressed, and different phases of the work were reached, men were retrained in the new skills. Considerable EEC grants aid was given to help with the training. The labour relations at Dinorwig, at a time when there was considerable unrest elsewhere, are reckoned to have been exceedingly good. There were regular consultations between management, workforce and local communities, with Local Liaison Committee meetings every month, at which any problems were aired and resolved.

Environmental issues included maintenance of water quality (there was daily, weekly and monthly sampling at up to 20 sites), protection of salmon and trout stocks, preservation of the Arctic Charr, and revegetation of upper dam and lower works, as well as the most costly part of the environmental care – undergrounding of the transmission line from Dinorwig to the National Grid, Landscaping was undertaken by one of the leading landscape architects, Sir Frederick Gibberd.
Detail from above


As regards future energy use – pumped storage at the present time uses night time electricity production from 'base-load' (generally very large or nuclear) power stations. So it is not really a 'renewable resource' station. However, if there were a great deal of renewable energy in the future, all round the world, then pumped storage would be vital – e.g. solar energy is only produced during the day, and depends on the degree of sunlight; tidal energy varies on a monthly cycle, hydro depends on rainfall, wind is seasonal, variable, and unpredictable. The best way to store energy so produced is to use pump storage.

By Denis Egan - https://www.flickr.com/photos/theancientbrit/545879229/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=15817352



Saturday, 1 June 2019

Natural Gas and CHP and sometimes cooling

Combined Heat and Power Systems

Using energy efficiently has become a goal across industries in the past decade. Rising energy prices, an increasingly competitive marketplace, and environmental regulation of harmful pollutant emissions have all incited commercial and industrial energy users to search out the most efficient and cleanest ways to use energy.

One innovation that is finding applications in commercial, industrial, and even residential settings is what is known as Combined Heat and Power (CHP) systems. Essentially, this type of system takes the waste heat from the burning of fossil fuels and applies it to power another process. For example, a basic CHP system might generate electricity through a large gas-fired turbine. The generation of this electricity would produce a great amount of waste heat. A CHP system might apply it to heating an industrial boiler instead of allowing this heat to escape. In this way, more of the energy contained in the natural gas is used than with a simple gas turbine. This increases energy efficiency, which implies that less energy is needed to begin with (costing the user less), and fewer emissions are generated because a smaller amount of natural gas is used. Typically, a CHP system produces a given amount of electricity and usable heat with 10 to 30 percent less fuel than would be needed if the two functions were separate. A typical electric generation facility may achieve up to 45 percent efficiency in the generation process, but with the addition of a waste heat recovery unit, can achieve energy efficiencies in excess of 80 percent.

Combining Heat and Power gives big efficiency improvements
CHP systems can be implemented to produce as much as 300 megawatts (MW) of electricity, to as little as 20 kilowatts (kW) of electricity, depending on the electrical and usable heat needs of the facility. It is not uncommon for larger cogeneration units to be installed in a facility that has very high space and water heating requirements, but lower electricity requirements. Under this scenario, the excess electricity is easily sold to the local electric utility.

Types of Combined Heat and Power Systems

A typical CHP system consists of an electric generator, which can take the form of a gas turbine, steam turbine, or combustion engine. In addition to this electric generator, a waste heat exchanger is installed, which recovers the excess heat or exhaust gas from the electric generator to in turn generate steam or hot water.

There are two basic types of CHP systems. The first is known as a ‘topping cycle’ system, where the system generates electricity first, and the waste heat or exhaust is used in an alternate process. Four types of topping cycle systems exist. The first, known as a combined-cycle topping system, burns fuel in a gas turbine or engine to generate electricity. The exhaust from this turbine or engine can either provide usable heat, or go to a heat recovery system to generate steam, which then may drive a secondary steam turbine.

The second type of topping cycle systems is known as a steam-turbine topping system. This system burns fuel to produce steam, which generates power through a steam turbine. The exhaust (left over steam) can be used as low-pressure process steam, to heat water for example.

The third type of topping cycle systems consists of an electric generator in which the engine jacket cooling water (the water that absorbs the excess emitted heat from an engine) is run through a heat recovery system to generate steam or hot water for space heating. The last type of topping cycle system is known as a gas turbine topping system. This system consists of a natural gas fired turbine, which drives a generator to produce electricity. The exhaust gas flows through a heat recovery boiler, which can convert the exhaust energy into steam, or usable heat.

While topping cycle systems are the most commonly used CHP systems, there is another type of CHP system known as ‘bottoming cycle’ systems. This type of system is the reverse of the above systems in that excess heat from a manufacturing process is used to generate steam, which then produces electricity. These types of systems are common in industries that use very high temperature furnaces, such as the glass or metals industries. Excess energy from the industrial application is generated first, and then used to power an electric generator second.

In addition to these two types of systems, fuel cells may also be used in a CHP system. Fuel cells can produce electricity using natural gas, without combustion or burning of the gas. However, fuel cells also produce heat along with electricity. Although fuel cell CHP systems are still in their infancy, it is expected that these applications will increase as the technology develops. To learn more about fuel cells, click here.


Combined Heat and Power Applications

CHP systems have applications both in large centralized power plants, and in distributed generation settings. Cogeneration systems have applications in centralized power plants, large industrial settings, large and medium sized commercial settings, and even smaller residential or commercial sites. The key determinant of whether or not combined heat and power technology would be of use is the nearby need or purpose for the captured waste heat. While electricity may be transferred reasonably efficiently across great distances, steam and hot water are not as transportable.

Heat that is generated from cogeneration plants has many uses, the most common of which include industrial processes and space and water heating. Those facilities that require both electricity and high temperature steam are best suited for CHP systems, as the system can operate at peak efficiency. There are many industries that require both electricity and steam, for example the pulp and paper industry is a major user of CHP systems. Electricity is required for lighting and operating machines, while the steam is useful in the manufacturing of paper.

Many commercial establishments also benefit from CHP systems. Universities, hospitals, condominiums, and office buildings all require electricity for lighting and electronic devices. These facilities also have high space and water heating requirements, making cogeneration a logical choice. For example, the University of Florida has an on-campus 42 MW gas turbine cogeneration facility that produces electricity and space and water heating for the campus. For more information on this cogeneration system, click here.

CHP systems are also available to serve smaller sized facilities. In this type of facility, these smaller, ‘modular’ cogeneration units can generate anywhere from 20 kW to 650 kW, and produce hot water from engine waste heat. It is most common to install a system based on the hot water needs of the establishment. For facilities like restaurants or medical facilities, which require hot water year-round, cogeneration makes an economic and environmentally friendly option. In terms of household sized CHP systems, it is possible to install a small system that can generate up to 10 kW, and fulfill all of the household heating requirements of an average home. However, these types of systems are not common. Fuel cell manufacturers are expected to target these small sized cogeneration units once the technology is perfected and it is economical for a household to install such a unit.

To learn more about CHP systems and explore other internet resources, visit the United States Combined Heat and Power association.

Icelandic Expertise to Bring Geo-Thermal to Ethiopia

by Ragnhildur Sigurdardottir, Bloomberg

Reykjavik Geothermal, a power developer backed by hedge fund billionaire Paul Tudor Jones II, is about to kick off a $4.4 billion project to bring geothermal energy to Ethiopia.

Tapping long-built Icelandic expertise in channeling geothermal power, the developer is preparing to start exploration drilling in September for two 500-MW plants in Corbetti and Tulu Moye, south of the capital Addis Ababa. At full-scale, each project would become the largest independent power producer in Africa, according to RG.
The Reykjavik-based company’s exploration teams have picked spots to drill where they can see steam rising from the ground. “All the results from the surface exploration work indicate that we are developing projects in a huge caldera, huge active volcanoes which can sustain at least 1,000 megawatts or more,” Gunnar Orn Gunnarsson, RG’s chief operating officer, said in an interview in Reykjavik.
Nesjavellir Geothermal Power Station, Iceland

The projects would become a vital cog in Ethiopia’s drive to become a middle-income country by 2025. Currently, its installed electricity capacity of 4,200 MW only provides power for 40% of its 105 million people. Neighboring Kenya already has 685 MW of installed geothermal capacity, providing almost a third of its energy.

The projects will cost money and need more investors to reach full potential. The first phase will develop 50 to 60 MW, requiring an equity investment of $175 million for each. They have been fully funded and RG holding a significant minority share in each project.

Bringing the full projects on-line would cost about $2.2 billion apiece, with 75% anticipated to be financed via debt. Other owners in the projects include Africa Renewable Energy Fund, Iceland Drilling Co. and Meridiam SAS.

RG expects “strong emerging market returns” from the projects, which will continue to improve as the projects gain scale, according to Gunnarsson.

Gunnarsson said RG is “fortunate” to be backed by Tudor Jones, who owns 23%, and Ambata Capital Partners, which holds 27%.

“But as the scale grows, RG continues to seek further investors,” he said.

The company is now negotiating drilling contracts after getting everything in place with the government, according to Gunnarsson. The projects have been in the works since 2010, through three prime ministers.

“Our relationship with the government has always been very positive and the current government is very supportive,” he said. “They have shown, in particularly over the last year, that they want this to happen and now we have cleared the pathway to go to exploration drilling.”


Tuesday, 11 April 2017

Are Green Energy Policies Effective - or are they all Failures

Whilst this article [Link Below] mainly blames the politicians, the main issue it neglects to cover with regard to cleaner energy methods [Wind, Sun, Tides and Bio-Digesters] is that of the distortion that misaligned subsidies have.

The initial subsidy for Solar Photo-Voltaic [Solar PV] was so over-generous that a massive 'industry' of direct-selling organisations sprang up almost over-night. These panels soaked up so much subsidy that the scheme has been massively cut back - so who set the original subsidy at 44p per kWh? Way, way over the current retail price of electricity - and not into the best technology either.

Now efficiency of 'renewables' [cleaner technologies is a better description; and certainly not wood pellet burning technologies] is often slated as the reason whey they are not effective or efficient.

  • Now the photo below shows steam [yes STEAM] rising from the cooling towers [yes COOLING TOWERS - not Chimneys] - probably Drax with a total of 8 Cooling Towers, ARE DESIGNED TO WASTE AROUND 60% of the energy released from burning Coal or even wood pellets - its the engineering answer to "efficient energy production" [...of a large scale remote power station].
  • Power Station Cooling Towers Wasting 60% Heat
  • However the electricity generated under centralised power plants like this is rarely above 22% at the plug in your house. Some say as low as 11%.


This in-efficiency [in centralised power systems] could have been solved by utilising lots of smaller power plants, built close to towns and cities which would not necessitate Cooling Towers, as waste heat can be distributed to houses and industry - just like in Denmark. Its called de-centralised power or even embedded power where tiny street corner electricity and heat for distribution are generated. So these remote [centralised] power stations are part of our problem.
Embedded Power Islington

Tidal projects also suffer from 'pilot project issues' and unnecessarily high subsidies - so the technology is fine, the "power" is clean and there is zero fuel cost - so lets look into differing cost models and subsidy strategies - this is the problem - how to assist innovation.

Dailymail online/debate/Christopher-Booker

Friday, 24 March 2017

Turn Down Markets

Innovative, carbon free ‘turn-down’ demand response sector delivering for consumers

23 Mar 2017

Capacity Market results announced today mean dozens of industrial and local businesses will help keep the lights on at peak demand next winter and cut carbon through innovation in the demand response sector, the Association for Decentralised Energy said.
Reducing Energy Loads

Approximately 312 MW of carbon free turn-down demand response has been secured as part of the Transitional Arrangements auction, which is aimed at preparing and supporting this innovative sector for the main Capacity Market auction.

The auction, which cleared at £45 per kW on Wednesday, means businesses across the UK will earn just over £14m in revenue, helping them to manage their energy costs and boost their competitiveness simply by turning down or shifting non-critical processes. Examples of demand turn down include temporarily switching off unnecessary lighting, pumps and motors, while demand shifting is the practice of moving a business process to earlier or later in the day.

There is nearly 10GW of untapped business led demand response, including highly efficient combined heat and power, ready to support the UK’s energy security. To achieve this potential however, user led demand response must be able to access all markets, from the Capacity Market and Balancing Mechanism to the Wholesale Market and ancillary services market, on an equal footing with traditional generation.

ADE Director Dr Tim Rotheray said:

"Today’s results are returning value to energy users for helping keep the lights on, while also cutting emissions through zero carbon demand response. Instead of paying power stations to increase supply, businesses will be managing demand in innovative ways while meeting all their energy needs leading to a more efficient, more affordable and lower carbon system.

"This auction is designed to help lower costs and improve uptake of demand response so that this tool will play a key part of the future energy sector. The Transitional Arrangements are vital in supporting this innovative sector to grow, deliver Britain’s security of supply needs and ultimately help drive a more competitive demand response market."

Notes to editors:

Auction results
A total of 373 MW entered the Auction, of which 83.69% received Capacity Agreements for delivery in 2017/18.