Staff picks: potential energy game-changers for 2021

W

hile buzzwords like “ground-breaking” and “innovation” often accompany investments in new forms of energy technologies, all cynicism aside, this could be a golden age of new power research.

The International Energy Agency reported in 2020 that, over the previous three years, renewable power received the second-most investment of any energy sector, behind only upstream oil and gas.

With gas investments falling from close to $500bn in 2018 to around $300bn in 2020, there is every reason to believe that renewables will soon see the most financial backing of any energy sector.

Indeed, renewable investments have been relatively unaffected by the Covid-19 pandemic, which shattered investment in the oil and gas industry, but left renewables relatively unscathed. Total renewable investment fell from $311bn in 2019 to $281bn in 2020, raising hopes within the renewables sector that the buzzwords so often associated with the industry could translate to meaningful long-term change in the energy industry.

It will not be conventional renewables that help drive this transition, either. Large-scale offshore wind farms, solar power facilities, and even hydropower dams are commonplace in many parts of the world. The challenges facing the renewable sector are less concerned with establishing new energy processes, and more with refining existing models.

With this in mind, there are a number of innovations within these renewable industries, from ultra-efficient solar cells to electricity drawn from the moisture from the air itself, that could help shift the world’s energy mix decisively in the favour of renewables.

While still somewhat controversial, perovskite solar cells, made of a perovskite-structured compound laying between transport layers and electrodes, have made real headway over the past decade. Recent signs show that the perovskites could be among the big game-changers for the renewable industry in 2021.

With the first perovskite photovoltaic (PV) developed in 2009, by 2012 the cell passed the 10% efficiency mark in the lab and kept making strides over the following years. Although in their early stages of commercialisation, due to concerns over their contact with moisture, perovskites have been passing longer and more extreme tests while setting efficiency records that outpace the progress made by mainstream PV.

According to Rethink Energy research, “perovskites [are] poised to disrupt solar supply chains everywhere”, and the answer to unlocking the technology could be to produce what is called a “perovskite-perovskite tandem”, where two or more materials absorb different parts of the visible spectrum.

For example, Oxford PV recently developed a 29.52% efficient tandem cell in the laboratory, a perovskite-silicon cell that converts 29.52% of the light touching it into electricity, while silicon PV has been stuck at 26.7% for several years.

It is now expected that over the course of 2021, Oxford PV’s first commercial modules will reach at least 27% efficiency and outperform the best silicon products on the market, which would be a significant milestone for the budding perovskite industry.

Another solar PV technology company, US start-up Swift Solar, which joins solar technologists from the universities of Stanford, Massachusetts, Washington, and Cambridge and Oxford in the UK, has also made noteworthy contributions to the field.

As a firm that exclusively explores perovskite-perovskite options, Swift Solar secured more than $8m in Series Seed 2 funding in December 2020, attracting much attention to what the company will do next with its overall equity financing of $16m.

While analyst group Rethink remains uncertain about the potential 30-year lifespan of perovskites, the company expects this efficiency gap to narrow in the future. For this reason, perovskites’ high theoretical efficiency is bound to overtake silicon efficiency on its own, and even quicker when paired with silicon.

Once such a perovskite-perovskite tandem is optimised, the technology’s current high price is expected to drop to much more affordable levels, thus enabling real market prevalence.

Hydrogen production and consumption is hardly new, though Covid-19 economic recovery packages have given a significant stimulus to the technology. Much of this has come in Europe, where funding from the EU and German Governments in particular has spurred the development of several electrolysers.

The next step in development could move hydrogen production offshore. Here, turbines would take advantage of ample resources of wind and water to create power delivered via pipeline, which creates obvious synergies with oilfields currently undergoing decommissioning.

Neptune Energy’s PosHYdon Project contracted DEME Offshore to install an electrolyser on one of its rigs in 2020. In the Netherlands, a consortium of companies collaborated with research institute TNO to start operating a 1MW electrolyser in 2021.

As transport decarbonises, this could even lead to mid-ocean refuelling ports, powered by floating wind generators. While this seems ludicrously ambitious, partnerships have already formed around similar projects using floating solar.

In Aberdeen, in the UK, the Dolphyn Hydrogen project promises to combine this with another exciting technology, floating wind generation. In 2020, the project won $3.9m of government funding to develop a 2MW prototype unit, which aims to launch in 2024 and would scale up to a 10MW commercial facility in 2027.

In Spain, Siemens Gamesa has collaborated with Siemens Energy to integrate hydrogen electrolysers into one of its operational turbine models, spending $146m over five years to create a demonstration unit in 2025/26.

In the nearer term, Danish wind giant Ørsted hopes to provide insight into the technology later this year. In January 2021, it made the final investment decision on its H2RES demonstration project in Copenhagen.

The company plans to use a 2MW near-shore wind turbine with onshore electrolysers to observe how electrolysers manage fluctuating power supplies. The 2MW facility would produce up to one ton of green hydrogen daily, with this going toward fuelling road transport.

Ørsted Offshore CEO Martin Neubert said: “H2RES will contribute with key learnings to turn Europe's ambitious build-out targets for renewable hydrogen into a new industrial success story.”

Expanding green energy availability to the level we need is no easy task, with neither wind, solar, or hydropower meeting the scalability requirements to see rapid, widespread adoption. With a view to moving past piecemeal renewable solutions, Eavor Technologies pitches its Eavor-Loop system as the “first truly scalable form of clean baseload power”.

Innovating on concepts in geothermal energy production, Eavor hopes to make geothermal a viable power source anywhere in the world – rather than being reliant on the underground reservoirs typically confined to volcanic environments.

The Eavor-Loop is formed by the connection of two vertical wells at the surface and underground, with many horizontal multilateral wellbores creating a closed buried-pipe system. Such a configuration would pump water independently through a thermosiphon effect – the different density of cold and hot water would mean that the cold pushes the warm towards the surface.

The company has recently raised $40m in funding, with backing from the investment arms of BP and Chevron. Those firms bring with them expertise in the drilling and infrastructure work that’s required to make Eavor-Loop successful, but their interest in Eavor also extends to a unique proposition the startup offers.

Eavor-Loop is a system with a relatively benign footprint – it takes up little space on the surface, and the system could be used to repurpose inactive well sites or decommissioned industrial facilities.

As the world moves away from oil and gas, the likes of BP and Chevron might find a future in the sorts of systems Eavor Technologies is looking to pioneer.

Perhaps one of the most striking power investments in recent years is the so-called “air gen” system developed by researchers at the University of Massachusetts Amherst in the US.

The technology, announced last February, comprises a generator that consists of a thin film made of protein nanowires, connected to a pair of electrodes. The film absorbs moisture from the atmosphere, which enables a small electrical current to pass between the electrodes, generating a current from little more than the air itself.

Electrical engineer Jun Yao, who worked on the project, declared that “we are literally making electricity out of thin air. The air gen generates clean energy 24/7”.

The process also boasts a number of advantages over other renewable power systems, such as wind and solar power, as its effectiveness is not limited by the environmental conditions in which it is placed.

The production of electricity is not hampered by cloud cover, weak tidal forces, or low wind speeds. Furthermore, the researchers demonstrated the effectiveness of the system indoors, raising the prospect of an entirely renewable energy source that can be deployed anywhere in the world.

However, the geobacter microbe, which produces the protein nanowires in the generator, was only discovered 30 years ago. Its characteristics in relation to large-scale laboratory work are relatively unknown, compared to more well-established chemical processes such as those involved in solar power.

A 2019 report co-authored by Derek Lovley, who first discovered geobacter and worked on the air gen research, noted that laboratory conditions could impede or accelerate the growth of electrically conductive pili.

These pili are the connectors required to form the electrical circuit at the core of the technology, the altered growth of which could lead to a “more than million-fold range in nanowire conductivity”. Such a vast margin for error poses a significant challenge to attempts to scale-up and formalise the technology for use at an industrial scale.