Elon Musk of Tesla electric car fame, has long realized that improved ability to store electricity is unquestionably the most important requirement for rapid transition from fossil fuels to clean energy, particularly solar. He has invested $1.4 billion in a 'gigafactory' to produce lithium-ion batteries able to store electricity generated by household solar panels, commercial power stations and for operation of electric vehicles. Such is the demand for these products, that orders for the total annual output of the factory have already been placed.
Imminent availability of these higher capacity batteries has already given increased impetus to further research and technology. Over the next 3-5 years this is likely to result in development of batteries which have greater storage density and are cheaper than the initial offering from Elon Musk which is priced at the margin of affordability. In an open market, such developments are inevitable, particularly where the most innovative and cheapest batteries promise to reap massive profits.
Why this pent-up demand? Because efficient, rapidly re-chargeable batteries offer huge advantages to owners and users of solar energy, making it a reliable, flexible and potentially cheaper source of electricity than produced by any fossil-fuelled power station.
In Australia, almost 1.4 million houses have solar panels on their roofs with capacity to generate over 130 MW of electricity. These dwellings remain attached to the grid which provides back-up electricity when solar panels do not generate sufficient electricity to meet domestic needs, for example on cloudy days. A large number of these dwellings also sell electricity to the grid when their solar panels produce energy which is surplus to domestic needs.
The 7 and 10 KWh "WallPack" batteries on offer from Elon Musk have sufficient capacity to reduce the need for grid back-up power supply to zero while at the same time improving the ability of the grid to access power generated by rooftop panels. Both batteries will be available in Australia in 2016 and are likely to stimulate rapid growth in the number of dwellings connected to solar panels on their roofs. Homeowners will be able to rely on solar panels for all their normal domestic electricity needs and increase income from selling surplus energy to the grid, should they remain connected to it.
Batteries will also enable dwellings in remote locations, particularly those not on the grid, to meet all their electricity needs from solar panels, replacing diesel powered generators where used. Diesel is expensive, particularly in remote locations. Sunlight is free.
Small and remote communities not connected to the grid can gain access to a 24 hour power supply by installing solar panels and batteries on individual dwellings and other facilities such as schools, aid-posts or water pumps and purifiers.
Larger remote communities not connected to the grid can gain access to electricity by constructing solar panel power stations of sufficient size to meet local needs combined with batteries attached to individual dwellings for use as back-up when the panels are not generating sufficient electricity or not operating at all, eg at night.
At present, commercial fossil-fuelled power stations have to be located in close proximity to their fuel supply, usually coal. They generate large amounts of pollution and electricity, the latter distributed via the grid to end-users possibly a thousand kilometers away. Consumers, whereever they are located, must be connected to the grid in order to get electricity which is normally available 24/7. However, connection to the grid may either be unaffordable or for remote and insular communities, impossible.
The advent of solar power stations, supported by newly available large storage of electricity, makes those stations a reliable source of energy supply on a continuous basis. Solar power stations are no longer tied to a fossil fuel source and can now be located in immediate proximity of end users, obviating the need for connection to a grid to provide back-up.
Competitive emphasis will shift to efficiency of solar cells used by the power station since use of the most efficient cells generates the most electricity. Coal-fired power stations feeding a grid become less competitive not only because solar power stations can be sighted locally but because they cost far less to construct and their fuel is free. Capital cost may fall further as photo-voltaic efficiency improves. Moreover, solar power stations are easily and more cheaply scalable and able to meet increasing, or contracting, demand.
The overall effect of these changes is that industry and residential properties can be supplied with a reliable source of electricity without the need for a grid or connection to it, irrespective of size or location of the properties. This provides enormous flexibility and reduces the cost of establishing business operations in the most appropriate locations, rather than locations where grid supply is available.
The future is electric but an interim measure has been the development of hybrid vehicles. They are propelled solely by electric motors supplied with energy from (1) batteries which are recharged from the mains (2) by a small on-board petrol motor driving a generator and (3) by engineering enabling the vehicles kinetic energy to charge the battery. Some hybrids use less than 2 litres/100km, with very low emissions.
The energy required to propel a purely electric vehicle must either be generated on-board or contained in pre-charged batteries which can either be rapidly re-charged or exchanged for fully charged ones. Electricity to keep batteries fully charged and propel the vehicle can be provided by a hydrogen fuel-cell.
The fuel-cell is a clean, efficient generator of electricity but is dependent on new infrastructure including increased production of hydrogen and distribution to a yet to be created refueling station. Hydrogen can be produced in the quantity required for fuelling electric vehicles by hydrolysis using solar generated electricity. At present, fuel-cell/electric vehicles have a range of 500-600 km before needing to be refueled.
However, hydrogen seems unlikely to supplement rapidly rechargeable batteries as the source of energy required for electric propulsion. Porsche has unveiled its 'Mission E' electric sports car with a range of 500 km on a single charge, powered by a battery pack which can be 80% recharged in 15 minutes. This provides clear evidence of the innovative and competitive nature of on-going battery development characterised by increasing density and rapidly reduced time for recharge.
Electric vehicles only become an affordable reality when their price is competitive with fossil fuelled vehicles. The most expensive component of an electric vehicle is the power unit, at present a lithium-ion battery pack and, to be competitive with fossil-fuelled vehicles, these have to be able to store electricity at $300/KWh. A 2010 analysis suggested that this would not be achieved until 2020. Present indications from Tesla and Porsche is that $300/KWh has already been achieved and will be significantly improved on by 2020.
By 2020 it is likely that electric cars will be comparably priced with fossil-fuelled vehicles and be the vehicle of choice. Mufflers, exhaust pipes, radiator and the internal combustion engine will then be rapidly consigned to history and replaced by the battery pack, continuous gear, and an electric motor on each axle or wheel.
Development of a durable, high density, rapid recharge battery which is now occurring, will result in use of solar energy for recharging and have a profound influence on the production and use of electric appliances powered by them. Hand tools, even the humble screwdriver, will be replaced by powered tools. Leaf-blowers, lawnmowers, pool and other domestic cleaners, forklifts, cranes, even toys, will be powered by batteries. Increased battery power will stimulate new innovations, increase productivity, reduce workload and extend what is possible.
Electrical appliances which we take for granted now such as laptops, tablets and mobile phones are likely to be equipped with batteries enabling their use for a week or more before rapid recharge is necessary. Electrically powered equipment, monitoring their performance and other facilities now manually operated in mining and agriculture will be battery operated and developed with capacity for remote control, as efficient solar generation and storage of electricity develops.
We are at the start of a market driven revolution which will sweep all before it, over-riding government ideology and policies. It will transform transport and have profound effects on the way we generate, save and use electricity. Best of all, the fuel source is free and globally available.