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



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 [at long last - when we consider that Sweden has been installing heat pumps for over 50 years - heck I remember learning about them on my Construction Degree in 1972]

  • · 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 well insulated fabric - or upgrading] 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 exchangers, compressors, buffer storage, expansion valves and circulation pumps – we can provide significant savings on initial capital costs and annual operating costs. 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 over dimensioned 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