The new large-scale Tesla Powerwall battery is important but perhaps not for the reasons you think, Joseph Mariathasan writes

Several friends of mine have now been for test drives of Tesla’s electric sports cars. I’m not convinced they were seriously thinking of buying one, but they certainly enjoyed the ride! Whilst Tesla’s sports cars have certainly been a hit, what the company may eventually become famous for is the development of large-scale Lithium Ion batteries, which could transform the economics of alternative energy sources. Chief executive Elon Musk unveiled the Tesla Powerwall last week. This device is designed to store energy at a residential level for load shifting, backup power and self-consumption of solar power generation. If it does fulfil its potential, it could be the first step towards a revolution in power generation.

Alternative power sources in the form of photovoltaic cells and wind energy have attracted huge amounts of government subsidies in an attempt to foster viable alternatives to fossil fuels. A key drawback for both is the fact they are intermittent providers of energy – you only get solar power during the day, whereas maximum demand for energy may be at night. Similarly, wind power cannot be guaranteed to supply energy when it is needed.

Another significant drawback is that they both require large amounts of space unlike conventional power plants, whether fossil fuel burning or nuclear. In Europe, with a highly developed grid supply, the need is for power sources that can be switched on and off to add power at times of peak demand. In emerging markets like India, the grid supplies do not even supply base power, leading to numerous power cuts, whilst more remote areas may have no electricity at all.

What Tesla’s battery technology represents is the final piece of a jigsaw that, if completed, could enable less developed countries to leapfrog into power generation in a similar way that many countries jumped into the mobile revolution. Anyone travelling to India will soon discover that the mains power supply is unreliable. Households and companies are incurring significant expenses in dealing with the problems of intermittent supply by buying back-up solutions such as diesel generators, diesel, etcetera. Moreover, large parts of many emerging countries do not yet even have access to the grid, and there are numerous places where it would be very costly to scale out the conventional grid.

What many emerging economies do have in plenty is sunshine, and the combination of much lower costs for photovoltaic solar cells and cost-effective battery storage systems could be transformative – particularly so if electric cars like Tesla’s become ubiquitous, as their batteries could be used to supplement home storage. Ajay Shah, an Indian economist, sees enormous potential for Tesla’s Powerwall in remote communities in India. Roofs could be equipped with photovoltaic cells, perhaps supplemented by diesel generators for peak loading, while battery storage could be used to by-pass the need to be connected to the grid.

But what the Powerwall represents is still just an incremental change to existing battery technology. Once you get beyond the hype, there are still many things that need to happen before the potential of battery storage can revolutionise power generation.

First, as Shah points out, higher oil prices would help to encourage the development of alternatives. He favours a global carbon tax, although I suspect this may be an issue for poorer countries. Second, in industrial countries, there needs to be continued government support for R&D and adoption of renewables and electric cars. Third, there needs to be continued worldwide scientific progress with batteries – Tesla’s product is relatively expensive for the power output it can produce. Fourth, Shah believes there needs to be sustained low interest rates globally for a long time, as these technologies require high capital costs but have close to zero running costs. And fifth, countries may needs electricity policies that give time-of-day pricing all the way to each household, ideally with a mechanism for distributed producers to sell electricity back to the grid at a cost that reflects that faced by the grid in delivering electricity to that location.

Tesla’s announcement is certainly of importance to both developed and emerging economies as a clear stepping stone to a possible future. But Tesla’s selling price to installers of $3,000 (€2,690) on top of the cost of solar cells, etcetera – together with a continuous output of just 20,00 watts that won’t make it powerful enough even for just a couple of domestic devices – makes it an unattractive proposition for the mass market.

However, what it does suggest is that technology is now making great strides in the right direction. The importance of the Tesla Powerwall may not be what it can do but rather its inspiring vision for the future. Even if it takes another decade, the ability to have large-scale, low-cost rechargeable batteries may be far more significant than a flashy sports car.

Joseph Mariathasan is a contributing editor at IPE

Topics