You See Where this is Going, Right?
January 22, 2014
If Financial Times Gets It, Maybe Anyone Can
But Mr Musk is also chairman of SolarCity, the biggest installer of residential solar systems in the US, and it has just launched an eye-catching combination of his sprawling interests: battery packs for Tesla cars that store electricity from solar panels.
SolarCity’s battery system is not a widely affordable answer yet, analysts say, but it could still help advance important shifts in the way energy is used.
The system is being rolled out first to businesses because it is aimed at cutting a growing energy cost: the charges that utilities impose, not just for the amount of electricity a company uses, but for the level of power it needs at any point in time.
SolarCity says its battery packs can lower these so-called “demand charges” significantly by providing power when demand is highest, as well as providing back-up power during the outages that periodically plague the ageing US electricity grid.
The company is initially offering the system, known as DemandLogic, in places where demand charges are high, such as parts of California, Connecticut and Massachusetts, and hopes eventually to launch a system for households.
Still, battery prices are falling fast. Mr Jaffe says smaller lithium batteries, such as those that power laptop computers, now cost $200-$250 per kilowatt hour, compared with $1,200 three years ago, while larger ones used in electric cars are $300-$400 per kWh, half what they were two years ago. “We expect them to get cheaper and cheaper,” he said.
If solar energy storage does spread widely, it is likely to add to the headaches that solar power is posing to conventional utilities around the world.
The plunging cost of solar panels is already turning utility customers into competitors as households start generating their own electricity, especially during daylight hours when utilities have traditionally made the most money.
The big energy generators that still have to build and maintain expensive gas or coal power plants are starting to fight back in many countries, urging regulators to impose fees on people putting in new rooftop solar systems to help pay for the cost of a power grid they say is being used virtually for free.
The conflict is likely to intensify as solar generation continues to surge, and not just in countries such as Germany, the world’s biggest solar power generator.
Growth in the number of residential solar panel installed in the US was so strong in 2013 that it is set to be the first time in more than 15 years that the US has installed more solar generating capacity than Germany, according to forecasts from the GTM research company.
Researchers at Harvard have developed an inexpensive, high capacity, organic battery that uses carbon-based materials as electrolytes rather than metals. The researchers say the technology stands to be a game-changer in renewable energy storage by solving the intermittent generation problems faced by renewable sources, such as wind and solar. The battery offers large volume electricity storage not possible with solid-state batteries and at a fraction of the cost of existing flow battery technology.
Energy in flow batteries is stored in fluids held in external tanks, meaning storage capacity is only limited by the size of the tanks. As a result, larger amounts of energy can be stored than in traditional solid-electrode batteries. However, existing flow battery technology uses expensive metals, such as vanadium or platinum, as electrolytes, resulting in a high cost per kilowatt-hour of storage.
“The whole world of electricity storage has been using metal ions in various charge states but there is a limited number that you can put into solution and use to store energy, and none of them can economically store massive amounts of renewable energy,” says Professor Roy Gordon, the Thomas D. Cabot Professor of Chemistry at Harvard.
The Harvard approach utilizes the electrochemistry of quinones, organic molecules that are similar to molecules that store energy in plants and animals and are plentiful in crude oil and green plants. Using these naturally abundant and inexpensive organic molecules, the researchers have developed a metal-free flow battery that already performs as well as vanadium flow batteries, while using significantly less expensive chemicals and no precious metals.
“With organic molecules, we introduce a vast new set of possibilities,” says Professor Gordon. “Some of them will be terrible and some will be really good. With these quinones we have the first ones that look really good.”
“Imagine a device the size of a home heating oil tank sitting in your basement,” says study co-lead author Michael Marshak. “It would store a day’s worth of sunshine from the solar panels on the roof of your house, potentially providing enough to power your household from late afternoon, through the night, into the next morning, without burning any fossil fuels,”
The technology now faces a grueling testing process to assess the degradation rate over thousands of cycles, with early tests indicating no signs of degradation. A Connecticut-based commercial collaborator, Sustainable Innovations, hopes to have a portable demonstration model ready in around three years and will bring the product to market when ready.
Until now, the idea that unsubsidised solar power could make enough financial sense to be competitive with conventional electricity has been largely confined to the realms of environmental campaigners and renewable energy advocates.
However, as solar panels become more efficient and vastly cheaper, and household power bills keep rising, analysts at some of the world’s largest financial institutions say such a prospect is indeed possible – and likely to cause profound disruption in the energy industry.
“We’re at a point now where demand starts to be driven by cold, hard economics rather than by subsidies and that is a game changer,” says Jason Channell of Citigroup.