While Tesla Energy has been making its publicity rounds over the past year, its development is nothing new — it’s just the latest topic in the long and complicated conversation surrounding integrated grid technologies.
An integrated grid is a power system that uses distributed energy resources, which are smaller power sources that can be combined to meet regular demand. These systems combine natural, renewable energy sources, such as solar and wind, with lithium ion energy storage systems like Tesla’s Powerwall.
Arguably, Tesla and its CEO, Elon Musk, may have overestimated their claims about Powerwall, which purportedly allows users to achieve “independence from the utility grid.” While we may hope that homes, businesses, and cities will one day be powered entirely by wind and solar energy, Tesla’s claims are off-base — and threaten to overshadow the real progress that other companies have made in the race to create a sustainable future.
Powerwall Is Not A Universal Solution
We’ve looked at the way Powerwall works before: it’s a rechargeable lithium-ion battery that collects and stores energy throughout the day. And although its price tag sounds enticing — $3,000 for the basic model — its publicity tends to gloss over the fact that there are added costs associated with installation. Those costs are multiplied when you consider the fact that one Powerwall unit probably won’t provide enough energy for an entire home; one unit can hold 7 kWh of energy at a time, yet the average American home uses about 31 kWh per day.
Sadrul Ula — one of the leaders of the Sustainable Integrated Grid Initiative (SIGI) at the University of California, Riverside — noted that Powerwall has some useful applications in certain situations, if it makes economic sense to adopt the technology. “In areas where there’s only one power source,” Ula said, “the extra cost makes sense.”
But Ula also noted that Tesla’s claims about Powerwall allowing its users to go completely off the grid are only partially true. “You’d have to have a special inverter, which is not listed in Powerwall’s cost,” he said.
Even with a special inverter, the company’s claim that the battery can power a home during a power outage is similarly overzealous. Powerwall can only sustain the extra power for two to four hours at a time, depending on use. “If I’m off the grid and my Powerwall energy finishes in a few hours’ time, I’m out of power,” Ula said.
Other leaders in the renewable energy industry have expressed similar concerns. Phil Hermann, chief energy engineer of Panasonic Eco Solutions, told the Guardian, “Elon Musk is out there saying you can do things now that the rest of us are hearing and going, ‘really?’ We wish we could, but it’s really not possible yet.”
While Musk’s marketing team may have bitten off more than they can chew, there are still a series of steady advancements being made in the fields of renewable energy and integrated grid technology. Although we may not be able to go off the grid with Powerwall anytime soon, various organizations are working to get us there.
The Challenges And Goals Of Renewable Energy
Lithium ion batteries, also called Li-ion, offer higher energy and power densities, as well as longer lifespans, than other technologies — which makes them a prime resource for solar energy storage. And as evidenced by Powerwall, the batteries already have a definitive presence in renewable energy. But their largest challenge, and the issue that holds back widespread adoption, is their production cost.
Ula pointed out that solar panels have become far more affordable due to outsourced production, which explains why we now see so many black panels covering the rooftops of homes across sunny states like California. The hope is that Li-ion production will experience similar cost improvements over time, which the Electric Power Research Institute (EPRI) suggests may happen as a result of rapid increases in plug-in electric vehicle battery production.
Meanwhile, initiatives like SIGI are working to integrate technologies into models of renewable energy. “The technology is there,” Ula said,” and we have a number of battery systems for two megawatt hours. We are combining it with solar energy on campus [at the University of California, Riverside] … which optimizes solar power that is delivered when you need it.”
EPRI points out that the increased adoption of integrated grid models requires “interconnection rules, communication technologies and standards, advanced distribution and reliability technologies, integration with grid planning, and enabling policy and regulation.” To that end, SIGI is a concentrated effort to model the ways that renewable energy can reduce our dependence on a traditional utility grid.
For instance, one of the initiative’s goals with its electric vehicle project is to operate an electric, 30-passenger trolley in the city of Riverside, to monitor electric vehicle charging stations throughout the city, and to measure and minimize the resulting impacts and fluctuations on the city's power grid.
While electric vehicles are a clear step towards a more sustainable future, SIGI’s research is significant because it addresses a pain point among electric vehicle drivers: people want to be able to charge their cars faster than waiting overnight. However, utility companies are not fans of faster charging systems, which can overload the grid. According to Ula, if people were to charge 10 Teslas in the same neighborhood, most current power lines wouldn’t be able to handle the energy suck.
The biggest issue with Powerwall is its failure to account for the two biggest factors facing renewable energy initiatives today: cost and integration. Utility companies don’t want to support new technologies that their power grids aren’t ready to handle, which is why initiatives like SIGI and EPRI matter — they allow researchers to demonstrate, on a smaller scale, how integrated grids can pave the way for a greener future.
Ula’s hope is that renewable energy technology and Li-ion batteries will become a greater, more cost-effective possibility. “The only uncertainty,” he said, “is how soon.”