balancing , frequency response , voltage support and reinforcement deferral . In its initial paper the STA ’ s focus is on the interaction between solar and storage , and the value that can arise from the combination of both .
On the basis that storage is a long-term game changer , rather than a short-term market bubble , the STA ’ s focus is on laying the foundations to enable a sustainable solar + storage market to develop . These ‘ foundations ’ require the development of robust product and installation standards , working with stakeholders , to ensure safety and quality . It also requires a regulatory framework that responds to the unique characteristics of storage and ensuring that storage systems can participate fully in the markets they could service .
Storage needs to be clearly defined so that an appropriate regulatory framework can be developed at EU and UK level . This should result in a level playing field for the diverse applications of solar + storage across the power system . At this stage , direct financial support from central government for solar + storage systems may not be the right action , though other countries are providing stimulus to support the development of their storage sectors . Given the rapid progress in storage technology , it is likely the economics will be fundamentally more attractive by the time essential regulatory hurdles are overcome in the UK . The STA calls for a continuation of monitored field trials , which have already provided significant value through knowledge sharing .
This position paper identifies the STA ’ s initial proposed actions in the storage field . Over the coming year , the organisation will engage further with relevant bodies to ensure a consistent and strong message is heard on the benefits that solar + storage could deliver to the wider energy system . The STA will work with its members to enable them to develop a solar + storage market in the UK , ensuring high-quality , safe installations under a clear , supportive policy and regulatory framework .
What is energy storage ? Energy storage has existed , in different forms , for centuries . From storage heaters and hot water cylinders to pumped hydro systems , there are significant variations in scale , technology , cost and operations of different energy storage solutions . For those not familiar with the subject , a research note produced by the Parliamentary Office of Science and Technology ( POST ) in April 2015 and a recent paper by consultants WSP Parsons Brinckerhoff explain the different storage technologies .
In the past , energy storage mainly took the form of small-scale heat storage ( eg . domestic storage heaters ) or large-scale electricity storage ( eg . pumped hydro ). These played important roles in making the best use of the electricity system when demand was low and ensuring its security when demand was high .
More recently , the development of other energy storage technologies has accelerated , including batteries , compressed air , flywheels and hydrogen . In particular , the research and innovation by the automotive industry for electric vehicles has driven the costs of batteries down significantly . For example , the cost of lithium ion batteries has fallen from more than $ 3,000 / kWh in 1990 to less than $ 200 / kWh today . Breakthroughs are frequently made at an academic level , with Advanced Research Projects Agency-Energy – a branch of the US Department of Energy – recently announcing it had attained some “ holy grails in batteries ”. Innovation has not been confined to electrical energy storage , with companies such as Sunamp developing small-scale heat batteries .
The different technologies , locations and scales of energy storage systems lead to very different use cases and business models . The range of models , stakeholders and key players in these different sub-markets is an interesting and complicated landscape that will become clearer over the coming years .
Why is energy storage important ? A number of global trends explain why storage is strategically important in the long term .
Firstly , renewables ( solar and wind in particular ) are reaching , or close to reaching , parity across the world on a levelised cost basis with conventional centralised generation , either coal , gas or nuclear . This trend is set to remain , as in the long term the costs of renewables will continue to fall . Deutsche Bank analysis last year identified 30 countries and 14 US states where solar is at grid parity and this is set to spread to other nations over the coming years . Secondly , the move towards a low carbon energy system – accelerated by the agreement in Paris in December 2015 – is now a priority for governments across the world . The timescale by which this will be achieved , and whether this will be enough to avert dangerous climate change , is a source of debate , but the direction of travel is clear .
Thirdly , the combination of these political and technological drivers means decentralised renewables are likely set to dominate the world ’ s energy supply in the long term ,
providing cost benefits to consumers . Decentralised , ambient renewables such as wind and solar have a zero or very low marginal cost of generation but their generation profiles are variable . Consequently , supporting variable renewables through greater system flexibility is increasingly important for the development an efficient , low carbon and secure energy system .
For end-users , storage allows more solar to be consumed as it allows solar to be available around the clock . The benefits are clear and adoption is rapid ; in 2015 , 41 % of new solar PV systems in Germany were tied with energy storage .
For power network operators , flexibility , including demand side response ( DSR ), energy storage , interconnection and dispatchable generation plants , are vital for the integration of non-dispatchable renewables . Storage already provides flexibility in the power system , notably through pumped hydro , but the importance and diversity of storage systems is set to grow to enable this future energy system . For example , IEA modelling showed 310GW of additional electrical storage by 2050 could support the transition to a fully decarbonised electricity system across the United States , Europe , China and India .
In summary , there is a move towards variable renewables and more decentralised and flexible energy systems globally , which have benefits in terms of costs , carbon and certainty ( security of supply ). Storage can play an increasingly important role in this transition , which provides the potential for a vast market in the long term .
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