The Next Hurdle for Renewable Power: Overcoming Seasonal Intermittency

The Limitations of Renewable Power

Electricity production has the largest emissions of any sector, accounting for 37% of global greenhouse gas emissions. At the same time, in the race to decarbonise the global economy, electricity generation has set the bar in terms of technology development and deployment; not only do we know how to produce green power, but costs are falling, with the cost of solar dropping 90% over the past decade. The challenge is that renewables aren’t always available: We need affordable, reliable, constant electricity any day, any time, every year and we don’t know how. 

Intermittency, a Constant Problem

Every second of every day we’re using electricity. Even while we sleep, industry churns out materials, hospitals care for our loved ones, and data centres protect our treasured terabytes of photos, calendars, and files. As we decarbonise our energy systems, our dependence on electricity is going to increase; especially as we change the way we power transport and create heat. We need to mitigate the 37% of global greenhouse gas emissions from electricity production while at the same time preparing for electricity demand to triple by 2050 under a net-zero scenario (BNEF).

But there’s more. Net-zero power production comes with its own challenges. Nuclear fission plants take decades to build and require vast amounts of capital expenditure. Some renewables, such as hydroelectric, geothermal, and tidal are geographically constrained. Because of this, many have placed their hopes in solar and wind due to their drastically reduced costs, but even these face the challenge of intermittency, meaning they’re not always available when you need them.

To solve the challenge of intermittency, we can either adjust our electricity demand patterns to match those of renewable generation or we must develop methods to shift power generation in time. Demand response has a role to play in the future energy system, but globally, it will not be sufficient. There will always be certain base loads which will require constant and high power, for example, industrial manufacturing of metals, cement production, and chemical processing.

To give an indication of the scale of this challenge: currently, the global manufacturing of metals alone accounts for10% of annual greenhouse gas emissions. Many of the processes involved in the production of products, which are crucial to clean future growth, require constant electrical power supply. This electricity demand can be in the order of 10s of MW to GWs. We need solutions which provide reliable and resilient electricity under all circumstances with net-zero emissions.

Opportunities for Innovation

In recent years, innovation efforts have been focused on lightweight, short duration batteries  which are particularly relevant to the household electronics and electric vehicle industry. The demand for electric vehicles and batteries in electronics have played a part in the cost of lithium ion batteries falling 80% since 2013. However, lithium ion batteries are not designed to hold charge for long periods of time. You’ll notice if you leave your laptop unplugged for a couple of days, when you get back to using it often the battery will be flat and need recharging. This is due to standby losses, where the battery loses charge even when it’s not being used. 

In the future, we need storage solutions which are suitable for long periods of time able to cope with seasonal variations in renewable generation, not just daily variations. Until we have a technically suitable, cost effective solution, fossil fuels will continue to be needed to meet electricity demand at times of limited renewable supply. 

Nowadays, attention is slowly turning to long duration energy storage (LDES). LDES has a broad definition covering storage technologies able to discharge for any time over 4 hours, but neglecting to worry about the length of time energy is stored. However, seasonal storage is often neglected and is likely to be the key to enabling renewable uptake and the subsequent reduction in energy-related emissions.  

Technologies exist which are able to store energy for extensive periods of time (e.g. months); for example, gravitational potential, flow battery electrochemistry, and chemical storage such as hydrogen. Yet, none of these are yet being exploited at scale. Each and every one of these is constrained by cost in some way and some are constrained by space requirements. Gravitational potential is CapEx heavy and requires large systems to be able to store energy at a valuable scale. Flow batteries often use vanadium to overcome crossover losses, but vanadium is an expensive chemical meaning that Vd-flow batteries are over 3 times the cost of lithium ion batteries. Chemical storage, for example hydrogen or ammonia or methanol, struggles with cost due to round trip efficiency losses - for hydrogen, the round trip efficiencies are around 40%.

We believe there are options for overcoming these cost constraints through technological advances. In general terms, cost reductions could be achieved through changing materials, tackling standby losses, energy conversion advances, or innovative use of assets to bring down the cost per use. For example: flow batteries could be designed using cheaper, less-price-volatile chemicals within the infinite lifetime group; temporary diffusion barriers could be introduced to reduce standby losses of conventional batteries; direct ammonia fuel cells could prevent the need to crack ammonia back to hydrogen.

Creating Ventures

At Deep Science Ventures, we want to design an energy storage system which can offer reliable, resilient power to high power base load demand all year around. This solution will enable the provision of cost competitive constant clean electricity throughout the year. 

If you’re an expert in energy systems and storage, with a background in materials science, chemistry, physics, or engineering and are interested in becoming a founder, we want to work with you to develop a solution, techno-economically suited to the constant high electrical power needs of industry. If successful, you’ll join a team of 40 technically-minded, entrepreneurially-spirited individuals, as we ideate and develop the optimal solution to this problem. Once successful, we’ll recruit complementary co-founders and provide investment.

If you’re interested in becoming a Founder of a radical energy storage company,  please apply via this link!