Renewable energy continues to grow in popularity as non-renewable sources dwindle. The market is predicted to grow to a value of $777.6 bn by the end of this year as major energy companies and national governments continue to invest in green energy research and production.
As more and more energy providers seek to produce ever-increasing amounts of renewable energy, the major issue with its generation is storage. With energy generation dependent on the sun, the wind or the tides, having enough energy for consumers to access in their absence is imperative.
How will energy storage develop in the near future as we continue to divorce ourselves from the damaging effects of oil and gas?
Lithium-ion batteries of the future
Continuing developments in battery technology mean that batteries are more efficient than ever. Current Lithium-ion technology boasts 99% energy efficiency and is the most successful way of storing solar or hydro-generated power.
However, there are some issue that must be smoothed out before batteries can truly fill the needs of the renewable energy market.
Lithium-ion batteries presently lose around 10% of their charge each month, roughly 0.3% each day that they are left uncharged and unused. The need for long-lasting energy storage which can be accessed easily could mean that Lithium-ion batteries are not fit for service in energy grids due to their power wastage.
New Lithium polymer batteries being developed lose around 0.1% of charge per month. If this technology continues to advance, future renewable energy grids could reach much more efficient levels of back-up energy availability.
The price of Lithium batteries is also much too high for many companies to gamble with at present. Partner at Energy & Manufacturing Kurt Baes believes that lithium costs will need to drop by 50% to make them viable back-up storage solutions for energy grids to take up.
However, industry experts believe that the cost of Lithium will soon fall by up to 60%. If this is the case, Lithium technology would quickly become a useful alternative to gas-fired units in energy grids.
Gravity-based storage – a new way to keep Britain running?
A new technology being developed looks set to help regulate the supply of renewable energy in the absence of sun, wind or waves.
Gravity-based energy storage in the UK works through raising and lowering large weights to store energy. Specialised automated winches raise the weight using excess energy and can release it to generate and store power.
This is significant to renewable energy storage issues because gravity storage can produce energy at short notice and, through changing the speed the weight is lowered, can produce a large amount of energy quickly.
However, this energy can only be stored short-term for up to 14 hours. For this reason, gravity storage would more likely work better as part of a renewable energy system in which energy from gravity storage locations was used to supply large amounts of energy at short notice to reduce the burden on battery back-ups.
Additionally, major companies like Gravitricity and Heindl electricity claim efficiency of 80% or more while Lithium-ion batteries have an energy efficiency of 95+%. The issue of storage time means that gravity storage is restricted in its ability to supply power but could still be a useful way of using our natural resources to support other methods of energy storage.
As a renewable energy source, gravity storage takes up the least ground space, making it more attractive than the expanses of land needed for solar panels. It’s also reliable as it doesn’t depend on the sun, wind or sea in order to work. For this reason, gravity storage seems more of an auxiliary method of energy production which would need to be weighed against the cost for creation and management. However, reducing our dependence on non-renewable matters is an essential global objective that gravity storage could aid us in meeting.
As corporations and governments continue to see the effectiveness of renewable energy, developments in its storage should hopefully bring us closer to independence from harmful sources.
This article was written by Damon Culbert from Battery Experts, provider of portable batteries in South Africa.