The European Photovoltaic Industry Association (EPIA) has teamed up with its gas and wind counterparts, in an attempt to put forward joint proposals that will enable the next stage of a transition to a lower carbon energy system, according to Oliver Schafer, President of the EPIA.
Due to their intermittent nature, a further roll-out of solar and wind is becoming increasingly inefficient and impractical for countries in which progress has been rapid like Germany, where it sends prices tumbling during periods of peak generation and cannot always all be used usefully. “Solar and wind cannot be varied to match demand”, said Mr Schafer on the side-lines of a conference in London last week.
What’s more, he added that efficient back-up gas-fired generation – or some other relatively low carbon form of supply or demand flexibility, such as demand side management or storage – was essential for grid stability when renewable generation is low. Currently, he said utility scale combined-cycle gas plants were the lowest carbon option that was practical at the sort of scale required, and which could be quickly brought on or off-stream as the balance between renewables and demand changed.
But with the current market and regulatory models, gas and other flexible options are struggling to maintain or achieve commercial viability, effectively endangering the further roll-out of solar and wind. Mr Schafer said, that while it would not mean a zero carbon system, utility scale gas backup that allowed more renewables could ensure a much lower carbon system than today, with further progress dependent on technology.
“We have talked to Greenpeace and other environmental groups about this and they understand we need to cooperate with relatively clean fossil fuels like gas in order to expand solar and wind further, but they still won’t say anything positive about gas”, said Mr Schafer. The market must also be re-designed to reward low marginal cost renewables, as well as flexibility, he added, using an alternative to feed-in-tariffs.
He said many European utilities saw distributed solar (and wind), with its zero marginal cost, as a threat to both their profitability and to the future security of grid supply. In fact, it is the regulatory system that is the problem, according to Mr Schafer. “There is a need to revolutionise the system and market design away from simple kilowatt-hour sales to accommodate the next wave of renewables, bringing totals above 50 percent of generating capacity.”
Smart systems and storage also need to be encouraged, he said, development of which is already partly being driven by European and national obligations to accommodate more intermittent renewables, as well as more major offtake points and distributed generation. He noted there were already 3 million solar installations that grid operators must deal with, which produced 3.3 percent of Europe’s demand in 2013, from 90 GW of capacity. Electric vehicles will also both provide – as an aggregated storage system – and require – in the form of a more distributed system – greater system flexibility.
“There needs to be incentives for flexibility such as gas-fired generation, demand side management or storage… Technically there is no problem to roll out more solar, the barriers are regulatory – it blocks cooperation between solar and grid networks… We need smart regulations to enable a smart grid and more renewables”, said Mr Schafer.
He said the solar, wind and gas associations would release an initial paper in early 2015. The groups are working closely with the European Commission, but competing political pressures were muddying the waters at national level. Germany, for example – clearly pro-renewables – is also promoting a capacity market system similar to the UK’s to ensure its coal sector is protected. That would pull the utility business model in two directions, as such an option is designed to support base-load providers, and does not encourage the flexibility needed in a more renewable-based, distributed and smarter system.
“We don’t want to protect the past, we need to build the future – if you want to increase solar [and wind] installed capacity further then a system redesign is needed.” In the UK, National Grid’s System Operability Framework report highlighted 15 areas where new developments were putting pressure on the grid, some of them critical. Also attending the conference, Martin Wilcox, head of future networks at UK Power Networks (the DSO for SE England) agreed: “UK regulation is 20 years old; it didn’t envisage these issues.”
New regulatory models could include options or insurance systems to guarantee supply or lower demand, according to Mr Stephen Woodhouse, director at consultants Poyry, who was speaking at the same conference. Options would be available for different classes of flexibility, including gas-fired back-up, aggregated demand side management and, as they become more economic, the various forms of storage. He added that Poyry was in discussion with the Irish regulator on this matter.
According to Andrew Jones, of S&C Europe, a storage provider, California has said it needed to install 1.7 GW of storage to ensure it can meet its renewable objectives. However, most attendees at the conference disagreed that battery storage was yet close to becoming a commercial mainstream option, although Julian Nebreda, regional president of AES, noted that it had about 300 MW of storage operating on a commercial basis in the US – much of it in tandem with renewable plants – and was planning more.
So, while gas-fired flexibility may currently be seen as the only practical option to balance renewables at scale, storage – of the simple battery type or more ambitious approaches such Thuga’s recent Power-to-Gas system in Germany – and smart grid-driven demand side management, may not be far behind.