The Switch meeting report

Chris Goodall is a renowned expert on new energy technologies with a website at: The following are notes from his talk to a joint meeting on 26 June 2017 on the future of solar power and energy storage.

Chris started by explaining that solar power is a thousand times more abundant than any other renewable source. Over the last fifty years, installed world-wide solar capacity has grown by 40% every year and panel costs have fallen dramatically. Panels costs have steadily dropped from $100 per MWp in 1976 to $10 in 1990 and then to under $1 in 2013. Trends for rapid expansion in solar power and for falling costs are continuing and expected to keep doing so.

In very sunny countries, solar electricity costs are already much lower than for any other competing energy sources. In 2016, costs under 3 cents per kWh have been quoted in Abu Dhabi and Chile.

Solar growth
Installed solar electricity capacity if growth continues at 40% – Source: Chris Goodall.

Wind power costs have fallen alongside greatly increased use too. In the right locations, this could occur for tidal lagoons (proposed for Swansea and other sites, including Bridgwater) and tidal current energy, such as the MayGen project by Atlantis Resources in North-East Scotland.

With growing renewable generation, solutions will be needed to keep electricity demand in line with the intermittent supply, as renewable energy generation varies over the day and between seasons.

In very sunny countries with good solar generation throughout the year, rapidly developing battery technology should be enough to keep demand and supply matched.

Sonnen home battery
A stylish Sonnen home battery.

In the UK and Europe, more measures will be needed, but battery storage will be part of the answer. Industrial and eventually domestic users will receive incentives, such as payments or lower non-peak costs, to switch off some of their electricity demand, when supply is insufficient. Only arranged suitable appliances and processes will be switched off, facilitated by automatic technology and smart metering. This is already increasingly common in industry and the Brooklyn microgrid is an interesting community trial.

To meet seasonal variation in demand with renewable energy, the UK will need a method of converting solar energy into biogas and biofuel – both to meet demand for these forms of power where still needed and to use for generating electricity when this cannot be met directly by renewable sources. Potentially, there are many methods for doing this conversion. Chris believes the most promising is to use electrolysis of water to make hydrogen, which can be combined with carbon from biomass (special crops or food waste) to create methane. This can then be used like conventional gas and also converted to make plastics and biofuels. The biogas and biofuels can be stored in existing storage tanks and distribution networks.

Copenhagen methanation plant
Electrochaea methanation plant in Copenhagen.

Chris believes that within 3 years, solar power will not need any subsidy in the UK to compete with other electricity sources, including gas-fired generation. But solar power can not be subsidy-free yet and, so until then, steady government policies and the right market structure will be needed to support the UK solar industry and allow it to grow.

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