Page 6 - OffGrid East Coast Special Edition 2016

Bringing solar power home
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If you’re not quite ready to go off grid but you’ve long dreamt of lowering your carbon footprint and becoming energy self-sufficient, here’s some great news: the technology and economics of solar power systems are getting better every day.
Here’s a quick overview of grid-tied solar power systems: components, costs, payback and pitfalls.
Components
Solar power systems consist of three main components: panels; mounting systems; and inverters.
Panels, the visible part of solar systems, have been the focus of much research and development in recent years. As a result, they now cost a fifth of what they cost just five years ago. The most common size is 250 watts, about one meter wide by 1.5 meters long. Solar arrays can include as few or as many panels as desired. Panels typically carry 25 year warranties.
Panels can be mounted on the ground, on poles or on rooftops. Rooftop installations are most discreet. Ideally, roofs should be south-facing, steeply pitched and shade- free.
Inverters are electronic devices that take the power
generated by panels (low voltage direct current) and convert it into grid-compatible power (120 volts, alternating current). Solar systems can have a single large inverter (the disadvantage being that the entire system goes down if it fails) or a small inverter for each panel (the advantage being that failure of an inverter affects only one panel). Systems with the latter option are most easily expandable.
Sizing
In New Brunswick, you can produce whatever power
it takes to lower your annual bill to zero. The ‘annual’ part is important: it means you can feed a surplus into the grid during the bright days of summer and then draw down that surplus during the dark days of winter. However, you won’t get credit or compensation if you feed more into the grid than you use on an annualized basis (and accounts are reset every March 31).
The number of panels required by a home depends
on how many kilowatt-hours are consumed annually,
as indicated on a power bill. A qualified installer can review your bill and tell you what size system you
need. Efficient homes may be able to achieve energy- neutrality with a 5-8 kilowatt system; the average home would more likely need a 10-12 kilowatt system. An array that size would cover most of a typical roof.
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