If you were one of those 18,000 households that lost power as Hurricane Imelda brushed past Bermuda this month, you might want to think about going solar.
Thanks to advances in technology, homes with an adequate number of charged batteries accompanying their solar panels can now enjoy power even as their neighbours suffer an outage.
And many residents are getting on board and feeling the benefit.
“Batteries are definitely becoming a bigger part of the investment,” said Jo Frith, chief sales officer at BE Solar.
Financial savings on monthly bills, of course, are still the number one driver behind the increasing sight of solar panels on Bermuda’s roofs, as well as people’s desire to become less reliant on polluting fossil fuels.
But Ms Frith said: “Whereas before, the solar and energy efficiency was an important first investment, now, when people are looking at it, they’re considering batteries as part of that first step. That’s because they want back-up power during an outage and they see value in having that, in conjunction with saving money on their Belco bill.”
How do solar batteries work?
BE Solar installs Enphase IQ 5P battery systems and was the first company in Bermuda to do so. The system controller, which Ms Frith referred to as the “brains of the system”, acts as an automatic transfer switch. This goes on when the grid switches off.
“When that switches over, you basically create a micro grid, which means that you’re using the solar panels’ electricity during the day to offset energy loads and excess energy charges up the battery.
“Then, at night time, you’re running off of the battery system. Then, as soon as the grid comes back on, it switches back over to the grid.”
This, she continued, happens so seamlessly that the lights don’t even flicker. Customers often don’t realise there is an outage until a neighbour calls asking why they have power or they see the notification on their phone.
Enphase solar systems also come with an App which gives real time data so homeowners can understand how their property is using and producing energy.
It also allows them to control the charging and discharging of the batteries so they can ensure their batteries are fully charged when a hurricane is imminent.
“You basically set it to full back up and it means that the batteries will remain fully charged,” Ms Frith explained.
You also have the option to use the batteries on a daily basis through self-consumption.
“Self-consumption allows you to charge up the batteries and discharge them so you can rely less on Belco.”
Upfront costs
While solar panels and batteries reduce electricity bills, there are upfront costs for installation. How quickly they will pay for themselves depends on your existing electricity bills and the number of panels you have installed.
There are always variables, but, for example, a home with a monthly Belco bill range of $200 to $250 might be recommended 10 solar panels costing $21,000. Expected annual electricity bill savings would be $2,651, meaning the panels are paying for themselves in under eight years.
At the higher end, a home with a monthly Belco bill range of $550 to $700 might be recommended 30 solar panels, which would cost $46,756. They can expect annual savings of $7,706 meaning they would pay for themselves in just over six years.
On top of that, is the cost of batteries. These, she explained, are modular. The first one is the most expensive because it includes the system controller, but this only needs to be done once, even if you add more batteries to the system.
Each battery block contains five kWh (kilowatt-hours), which, Ms Frith said, “will help run a water pump and a fridge.”
She added: “A 10kWh battery system will start to run more things such as ceiling fans, Internet, lights, fridge, water.”
The cost for the first battery, with the system controller, is about $26,000 and each additional battery costs about $6,000. If you have the budget to install solar panels and batteries at the same time, however, that is more cost effective as there won’t be any doubling up of labour and administration. This is because the costs include the planning application, Belco interconnection, all labour, all materials, final commissioning and setting up the monitoring.
In this case, for a family of four, for coverage during an outage, she would recommend around 15 solar panels and a 10kWh battery system. This, she continued, “would probably be around a $40,000 investment,” for a turnkey project that included absolutely everything.
The future of solar energy
Now that solar panels and batteries are becoming the norm, what is next in the solar energy pipeline?
“Vehicle-to-grid, or bi-directional charging,” Ms Frith said. This basically allows you to power your house using your electric vehicle battery, as long as the vehicle is bi-directional or vehicle-to-grid compatible.
“You can also set parameters on these vehicles for the utility to pull from your car in times of intermittency,” she continued. This means that even when the sun isn’t shining, as long as your bi-directional electric vehicle is plugged in, you can use the car battery instead of relying on Belco.
Bi-directional electric vehicles aren’t for sale in Bermuda yet, but she hopes this technology will be fully available sometime next year.
Once on the market, could this make wall-mounted batteries obsolete? Possibly, but there is one catch: If your car’s not at the property, you can’t use it to power your home.
Ms Frith said: “Maybe there is still an element of batteries on the wall, but not as many because you’re using your car in tandem with the system. That’s really exciting technology for Bermuda and I think it’s got a lot of potential.”
