By Andrew Ritch
As the installed costs of solar systems continue to fall and adoption rates continue to increase, roof-mounted solar systems have become an increasingly popular option for business owners looking to save money and lock in their energy costs.
However, while simple in concept, there are many complicated elements that go into determining whether solar energy is viable for a given building. Here are the key factors that need to be addressed.
How much energy do I need to generate?
This is the starting point to properly evaluate whether a potential solar energy system makes sense. You want to plan for a system that does not consistently generate and export energy back to the power grid.
Building a system that is too small prevents you from realizing the benefits of going solar; but building one that is too large upends the project’s economic viability. That’s because in most cases, excess energy generated cannot be stored. (That is, not until battery storage becomes more affordable and efficient, something that is not too far in the future.) While it is possible to “sell” your excess energy to the grid, the (wholesale) price that the utility will pay for your energy is oftentimes nowhere near enough to offset your cost of generating it.
Bottom line: when it comes to sizing your solar energy system, you want to build to need - or forecasted need - and no more.
Can my roof support a solar array?
You’ll need to figure out the actual, usable amount of roof space that you have (considering obstructions such as skylights, vents, etc.) and check this against the amount of energy you’d like to generate. You’ll also need to account for factors such as the slope and direction of your roof. Roofs that face either south or west generate the most energy. And the angle of the tilt of the panels towards the sun matters, too.
Don’t forget to assess the current condition of your roof. If your roof is at or near the end of its useful life, then it most likely doesn’t make sense to install solar panels on it. Rather, get it fixed or replaced beforehand to reduce the risk of having to dismantle an installed solar system to make repairs later.
You also want to consider whether your roof can handle the additional weight of the solar equipment. The very last thing that you want to do is to make the structure unsound by adding weight that the building wasn’t designed to handle. If there’s even a question about this, have a structural engineer take a look. And while they’re at it, have them assess the risk of upward lift on the roof due to wind that could get under the solar panels.
As you can see, there are a lot of factors to evaluate when it comes to installing a solar array on a roof. If your roof isn’t viable, don’t lose hope. If you have enough open land nearby, that could be an alternative.
Do I need to stay connected to the grid?
With few exceptions, yes. In most cases, going solar does not mean you can completely disconnect from the grid. Solar will reduce your reliance on the utility grid, and thus save you energy costs (not to mention the benefits to the environment), but it generally won’t completely eliminate it.
Most utilities require an interconnection agreement, which is a written notice to the utility describing the details of one's plans to construct, install and operate any electricity generating system which will be connected to the grid. This must be submitted to the utility and approved prior to the start of construction. The purpose here is to ensure safety (e.g. first responders) and grid reliability.
What kind of returns can I expect from going solar?
Today, you can expect an approximate payback period of around 5-7 years on solar. This is down quite a bit from previous years due to solar equipment becoming more affordable and efficient.
Since there is still a considerable investment being made, choosing the right contractors and installers is quite important, as is selecting quality components.
There are also financing alternatives such as PACE that could be used to reduce the cost of solar projects as well as cash incentives and rebates to help bring down costs. If you’re not familiar with PACE, start here.