A Snapshot of Energy Innovation from the Rushlight Summer Showcase

Last week I visited the Rushlight Summer Showcase in London. This brings together clean technology companies looking for investment and potential investors. The companies give a series of five-minute pitches to an investor panel, and there is also an exhibition where you get a chance to talk to the companies in a bit more detail.

This year there was a very strong emphasis on energy innovation with 34 projects from the Innovate UK Energy Catalyst programme and 17 projects from the BEIS Energy Entrepreneurs programme. Companies cover the full range from early-stage spin outs to in the market and ready to scale. It was an excellent way to get an overview of what is happening in the energy innovation space, and to hear about some fascinating projects.

Among the companies exhibiting or in the showcase were a number I have met previously through the Clean and Cool Missions, or Innovate UK funding programs. It is always fun to catch up with companies as they zigzag their way from initial concept to full commercialisation. The lesson is that in the clean technology space success takes time, and the journey is rarely straightforward.

I did not get a chance to talk to all companies about their projects, but these are some of the ones that grabbed my attention.

Renewable energy generation

There are still plenty of companies creating better ways to generate renewable and low carbon energy.

Rotaheat were demonstrating their system for generating usable heat directly from wind turbines and water wheels using a simple and clever magnetic braking system. Power outputs of 20kW are already available with larger devices in development.

Polysolar produce transparent photovoltaic glass to be integrated into buildings. These panels could be an important development towards energy positive buildings that generate more power than they need to operate. Polysolar use a range of PV technologies from cadmium-telluride through amorphous and crystalline silicon to organic polymers.

Both these companies have products which are well understood and ready for deployment. At the other extreme is Tokamak Energy. Clean energy from nuclear fusion has been chased for many years, and it has often been said that energy generation from fusion has been 30 years away for at least the last 50 years. Giant multi-country collaborations like ITER are investing huge budgets over many years in the challenge. Tokamak Energy are trying to short-circuit the process using a compact spherical plasma vessel with high-temperature superconductors for the containing magnetic field. They plan to be delivering clean and abundant fusion power to the grid by 2030. That’s really going for the big prize!

Energy storage

Integrating distributed and intermittent renewables into the grid requires storage at both local and grid scale. One of the themes of the showcase was the opportunity for a range of solutions that offer different scales, different speeds of response and different peak powers.

Connected Energy was showcasing lithium ion battery storage using second life batteries from electric vehicles. This offers the flexibility and speed of battery storage with lower capital costs and a more sustainable approach by extending the useful life of the batteries.

Pumped hydro storage schemes such as Electric Mountain are very efficient, but are big civil engineering projects and can only be used in a few locations. Two water reservoirs at different altitudes are connected by large pipes leading through a turbine. When spare energy is available water is pumped from the lower reservoir to the top reservoir, and when there is a spike in demand water flows back through the turbine generating electricity. You need the right geography and lots of concrete.

Fleet Renewables plans to overcome these limitations by using a working liquid 2.4 times as dense as water. This means you need 60% less height difference between the two reservoirs. You could put a commercially viable system into something like an underground car park. They expect to be able to deliver energy storage at one third the cost of lithium ion batteries.

Highview Power store energy in the form of liquid air. Using standard cryogenic gas handling equipment they can use surplus energy to compress and cool air to -196 C, converting it into a liquid which can be conveniently stored in insulated low-pressure vessels. When warmed it turns back to a gas expanding 700-fold and driving a turbine to generate electricity. This technology is now ready for commercial exploitation, and at the beginning of June the world’s first grid-scale liquid air energy storage plant was opened in Bury, Manchester.

ITM Power has promoted the use of hydrogen as a long-term energy store for some time, combining efficient hydrolysis with advanced compression technology to provide a practical and distributable store. Their latest project is based at the European Marine Energy Centre in the Orkneys. Tidal turbines and wind turbines at the site generate more power that can be used locally. Unfortunately, the grid connections do not have sufficient capacity to distribute the excess power. Converting electricity into hydrogen allows it to be shipped to other locations where it can be used as a fuel.

Combined and integrated technologies

Another key theme of the showcase was technologies that provide multiple benefits, or are integrated into wider systems.

Naked Energy has developed a combination solar power system that tackles two challenges. The first is that photovoltaic cells lose efficiency as they heat up, and should ideally be cooled to maximise the amount of electricity generated. Secondly, the majority of the energy consumed by buildings in the UK is for space and hot water heating. This needs to be totally decarbonised if we going to meet 2050 targets. By combining photovoltaic cells with a heat transfer system in a vacuum tube, they are able to generate electricity and hot water at the same time. By controlling the temperature of the photovoltaic cells they are able to increase the yield of electricity from 200 W/m² for a conventional installation to 310 W/m². That means you need 40% less space for a given output, and you have a 65% better internal rate of return.

Origen Power has a really intriguing use of fuel cells that they say can deliver carbon negative energy. Natural gas is fed to a high-temperature fuel cell. About half of the energy released from the methane is converted directly into electricity and the rest is used as heat. Running the system at 660 C they can convert limestone into lime (calcium oxide). This process produces pure CO₂ which can be used in a range of commercial processes or stored in a carbon capture and storage system. Lime has a range of applications (cement) and when used will absorb CO₂ from the atmosphere as it converts back to limestone. So providing the CO₂ can be taken out of circulation, instead of releasing 400 g of CO₂ per kWh electricity, this system takes 600 g out of the atmosphere for each kWh generated. The minimum effective size for such a plant is 25 MW, and it needs to be integrated into a system that can use or store the CO₂, but it is estimated that such a plant would cost £36 million, have a 20 year life, generate £9 million in annual profit, and remove 86 kT CO₂ p.a. from the atmosphere.

Another fascinating project comes from Green Fuels. They have been active in the production of biofuels from food and agricultural waste for many years. Taking an alternative approach to producing fuel from algae, instead of trying to grow difficult organisms with a high oil content they are tapping directly into fish farming. Tilapia are fed on easy to grow algae, and after harvesting and filleting, fish oil is separated from the waste and converted into biofuel. The residue after oil extraction can be used as a fertiliser or as a fish food. In one possible example, a remote fish farm is powered by diesel generators, and all the fish waste is currently landfilled. Converting the fish waste into fuel they believe they can close the loop making the farm self-sufficient in energy and avoiding landfill.

Finally, a project I found intriguing, but which does not fit into my previous categories, comes from Flint Engineering. They have created a flat heat pipe using aluminium extrusions which maintains a constant temperature across its surface. Two initial applications are roofing panels and chiller cabinet shelves. The roof panels can be used for solar thermal production of hot water, or for cooling PV panels to increase efficiency (as with Naked Energy). The chiller shelves couple the cooling much more efficiently to the product and can save 20% of the energy when retrofitted to existing cabinets and as much as 30% of energy in new cabinets. A potentially exciting application is in domestic heating. Heat pumps provide very low carbon heating, but because their output temperature is not very high they are hard to use in wall mounted radiator systems, and it is not always convenient or possible to retrofit underfloor heating. These flat heat pipe panels could make much more effective use of typical heat pump output temperatures and could be a solution for the 26 million homes we have to retrofit to very low carbon emissions by 2050.

So a fascinating day, pages of notes, and some very interesting ideas to follow up on. My apologies to all the great projects I did not get a chance to look at in detail. More information is available from the Rushlight Events site.

And don’t forget, all of these companies are looking for investment to take these exciting projects to the next stage.