Question: I keep hearing about restaurants installing solar panels. How do they work? Is solar power a good choice for my restaurant? Will it really save me money?

Answer: Restaurants consume more than five times more energy per square foot than other commercial buildings, so it’s important to investigate every option when it comes to saving energy—and solar power is becoming a popular choice to help supplement restaurants’ power use. Chipotle Mexican Grill, an American chain, made green-news headlines in 2009 when it announced its intention to install solar panels on 75 restaurants. A variety of quick-service restaurants are experimenting with solar panels and other forms of renewable energy, including McDonald’s and Burger King.

But before you rush out and install a solar-power system in your restaurant, we’ll help you get familiar with the basics of solar power.

What is solar power used for?

The sun is a great source of free, clean energy. More energy falls on the earth in one hour than is used by everybody in the world during a year. The challenge? Converting that energy into something that’s usable for homes and businesses. As technology progresses, though, it’s getting easier and easier to harness the sun’s energy for home and commercial use. There are a number of ways solar energy can be used:

  • Solar water heating uses the heat of the sun to pre-heat incoming water, so your water heater doesn’t have to work as hard
  • Solar photovoltaic cells collect the sun’s energy to produce electricity
  • Passive solar designs use sunlight for warming and cooling living and working spaces

Each of these methods uses different types of technology to convert sunlight into usable energy.

How does solar power work?

Each solar technology is a little different, depending on its function.

Solar water heaters usually have two components: a solar collector and a storage tank. The most common type of collector is called a flat plate collector, which uses a thin box with a transparent cover, mounted so it’s facing the sun. Tubes run through the box and contain the liquid to be heated. The heated liquid is then moved, either passively or with a pump, to an insulated storage tank.

Photovoltaic cells use the sun’s energy to create electricity. Solar cells use silicon and other materials that create an electric charge when exposed to sunlight, to help power homes and businesses. Generally, solar panels are mounted on a roof or wall that faces south, and several solar panels can be combined for greater power generation. Second-generation solar panels are thin and pliable, allowing for greater flexibility in installation.

Passive solar design uses the sun to heat and cool spaces but, unlike the other solar power methods we’ve mentioned, doesn’t use special technology to collect the sun’s energy. Instead, passive solar design uses the design and placement of a building to take the greatest possible advantage of the sun. This can include south-facing windows to collect heat, a trombe wall (which is a south-facing wall painted black that absorbs heat during the day and releases it at night), and skylights and clerestory windows to make use of natural daylight instead of electric lights.

Is solar power right for my restaurant?

If you’re considering investing in solar power for your restaurant, ask yourself and your solar power provider the following questions:

  • Can I locate my system so that it works well? A south-facing exposure, clear of shade, is best for a top-performing system.
  • Is my property large enough for an efficient, effective system? You may need more space than you have for your system to work at its best. Your solar power provider should be able to assess whether you have sufficient space.
  • What kind of roof do I have? If you’re mounting a system on the roof, know that composition shingles are usually easiest to work with, while slate tiles are the hardest. If you need your roof replaced, it might be a good idea to do this at the same time as you’re installing your solar-power system. In fact, some solar panels can be incorporated directly into the roof itself.
  • How much power do I need? Work with your solar power provider to determine how much of your energy usage you’d like covered by solar power. This, and the size of your roof, will affect how big your solar system needs to be.
  • Are there rebates available? Some provinces offer incentives for installing energy-efficient technologies, including solar power systems. Take a look at the Office of Energy Efficiency’s list of available rebates by province.
  • What’s the payback period? This depends on how large your system is, how well-suited your location is and how much energy you use in a year. The payback period for solar water or space heating tends to be shorter than that for solar electricity systems because of the higher cost of photovoltaic cells.

Installing a solar-power system is an important step to reducing your energy costs and greening your restaurant.

Do you have experience with solar power in your business? Share your experience in the comments.

Image credit: Steve Snodgrass