USING SOLAR ENERGY AFTER THE SUN GOES DOWN
by Jonathan Kent
The rise of renewable energy is expected to be one of the strongest drivers of infrastructure development in Bermuda over the next decade.
The Integrated Resource Plan, the Regulatory Authority’s roadmap for Bermuda’s future power supply, targets 85 per cent of electricity coming from renewable sources by 2035.
Whether that lofty goal can be achieved will depend to some extent on private homeowners investing in solar photovoltaic systems.
Cameron Smith, managing director and cofounder of Greenlight Energy, has a good idea of what can add to renewables’ appeal.
“Due to the intermittent nature of renewables, it is absolutely essential that energy storage systems become just as mainstream as solar panels have,” Mr Smith said.
“In essence, solar panels only generate energy during sunlight hours. While excess energy can be sold back to the grid for about half as much as it is purchased for, it would make far more sense to store the excess energy to be used later as needed.”
Greenlight’s solution is the Tesla Powerwall 2, a rechargeable lithium-ion battery pack capable of storing 13.5 kilowatt hours, made by the company best known for its electric cars.
“We recommend that most people get two or three as the average homeowner uses about 27kwh per day,” Mr Smith added. “So two Powerwalls give you enough power to run your home for an entire day. That’s great for when there’s a hurricane or a blackout.
“They are stackable, so if you have enough solar panels and enough Powerwalls, you can go entirely without the grid. We believe this is how the future of the energy sector looks in Bermuda.”
The Powerwall 2 is 44 inches high by 29 inches wide by 5.5 inches deep and weighs 276 pounds. Greenlight also offers the Tesla Powerpack, which stores 210kwh, for larger commercial projects. Mr Smith said: “The Powerpack is the size of a small room. When we install one of those, we’re working closely with Tesla engineers.”
Battery technology is advancing at a rapid pace: Tesla’s Powerwall 1, introduced in 2015 stored less than half the power of the second version, launched just five years later.
“Power storage fundamentally changes the way people think about energy,” Mr Smith said. “It’s an exciting industry. We’re watching the changes happening. We’re seeing people going from consuming 1,000kwh from the grid a year ago to 100kwh today. They’re saving money on their bills and Bermuda’s cutting down on fossil fuels. It’s the right move for so many reasons.”
Two Powerwalls is the minimum number Greenlight recommends installing in a home, in order to build an effective storage system. Installed cost for each Powerwall is in the low five figures, Mr Smith said, and varies with the complexity of installation and the number of units installed.
Mr Smith acknowledges the upfront costs of a renewable energy system – ranging from tens to hundreds of thousands of dollars – puts off many people.
Greenlight, however, pays the entire upfront cost of a solar installation. The customer pays back the company over time, through a monthly repayment calculated at 31 cents per kwh of electricity generated by the system.
“The interest in renewable energy has never been greater,” Mr Smith added. “It’s never been easier to go green.”