Even in the golden age of renewable energy development, however, solar power accounts for less than 1% of global energy production. Solar power has made relatively small steps in comparison to other energy revolutions. So who would be so bold as to make the giant leap for renewable energy that might end the age of fossil fuels, other than South African-born innovator Elon Musk?
Only four years after the release of Tesla Motors’ latest electric car, the Model S, Musk announced the release of the company’s latest project, the Tesla Powerwall, an all-inclusive battery unit designed to store energy from solar panels. During his presentation of the Powerwall in Los Angeles, he described a gap between solar technology and a means to store its energy for use when the sun is not around. Musk described current battery storage systems as being unreliable, ugly, and “bad in every way”. Musk commented on how it is difficult to have batteries installed for solar panels because they need to be accompanied with an array of other systems like safety measures, thermal controls and converters, which would have to be individually installed, usually by different contractors. In his Powerwall address he said, “it’s designed to work very well with solar systems, right out of the box. It addresses all of the needs … You can actually, if you want, go completely off-grid.”
One Powerwall unit has a maximum capacity of ten kilowatt hours (kWh), not including the energy consumed and replaced during the day. According to data adapted from the US Energy Information Administration, the average American household consumes about 30.3 kWh a day. The Powerwall is designed to be stacked with up to 9 units at a cost of $3500 (approximately R40 000) per unit. The most expensive state with regard to energy consumption in the US is Hawaii, where the cost of 1 kWh is $0.33. To use the national grid in Hawaii with current prices every day for a year would cost about $3600, meaning that three years of energy consumption would account for the purchase of 3 Powerwall units. On average, a household in the US pays 12.19 cents per kWh and it would take 9 years to spend the equivalent of 3 Powerwall installations. Installing two or three of them could serve as a powerful solution in a remote area with no access to the electric grid, while electric grids that are more expensive or unreliable might also carry enough incentive to install a Powerwall.
Demand for the Powerwall and its larger, scaled-up sibling, the Powerpack, has exceeded Musk’s expectations with 38 000 reservations for the Powerwall being made within the first week of its availability. Bearing in mind that some reservations were for more than one unit, that comes to an estimate of 50 000 units or more, according to Tesla’s website. Tesla has also signed a joint deal with Panasonic to build what Musk calls a “gigafactory” in Nevada, USA, where the Powerwall and Powerpack will be mass-produced. Musk said that it will be the first of many gigafactories on US soil.
To demonstrate the scalability of his Powerwall and Powerpack, Musk announced that the entire building in which he was doing his presentation was being powered by sunlight stored in Powerpacks made visible in the back of the hall. He also described a “gigawatt-class” Powerpack installation which could potentially power entire cities. He said that it would take 160 million Powerpack units to replace fossil fuel electricity consumption in the US, and 900 million units to do the same worldwide. To transform all transport, heating and electricity generation in the world to renewable energy, 2 billion Powerpacks would be needed. Musk described this feat as “within the ability of humanity to actually do.”
Above and beyond its pragmatic perks, the Powerwall’s aesthetic appeal and space efficiency are what make it truly attractive. The battery pack is smooth and curvy, reminiscent of the sleek, futuristic look of the floating robot EVE from the film WALL-E. It can also be mounted on a wall as opposed to having a dedicated room built for storing conventional batteries. What’s more, it comes in whatever colour you want.