That’s great news! Converting your home to a solar system can make a big environmental and financial impact. Isaac Ost at Solar.com estimates that the average 5kW system “can produce an average of 350-850 kWh of AC energy per month. To put that into perspective, a typical household uses about 897 kWh per month.”
Installing any renewable energy system is also a big decision. A solar system can be extra daunting because the technology is evolving quickly and there are a lot of factors to consider. We hope this guide will help you explore the process and navigate some of the choices you’ll need to make once you decide to go solar.
Make Sure A Solar System is Right for You
There are a few key questions you need to ask yourself to ensure that this investment is going to pay off:
- How much in/direct sunlight do you get through the year?
- What direction does your roof face?
- What surface area can you devote to a solar system?
- How much energy does your household consume?
- What are your energy rates?
- How long will you be in your home?
- What is the resale value of green upgrades in your area?
Your geographical location, site situation, energy prices and energy usage should all play a role in determining whether a solar system is the right renewable energy system for you. That’s not to say that you shouldn’t invest in one if you live in an area with little direct sunlight or are planning to sell your home in a few years. You might just need to adjust your expectations of the financial benefits you’ll get from the installation.
Look for Grants
Solar systems are becoming more affordable, but they still aren’t cheap. The Center for Sustainable Energy estimates that “the average 5-kW residential system will cost $15,000-$25,000,” without accounting for grants and rebates. They note that the system will take an average of 6-9 years to pay itself off, “depending on the cost of the system and the utility bill savings.”
No sense leaving money for this project on the table, then. Many local, regional and federal governments offer some kind of tax incentive, rebate or grant program to help homeowners cover the costs of installation. Many governments also offer net metering. This lets homeowners feed any excess power back into the grid and gain credits to offset their electricity bills in times of low solar yield.
In the U.S., the Solar Investment Tax Credit is available nationally. To find out what you might qualify for state-by-state, visit DSIRE (the Database of State Incentives for Renewables & Efficiency). If you’re in Canada, Solacity offers listings of incentives by province, as well as federally. In the U.K., check out the Smart Export Guarantee. The Australian government is currently running the Small-scale Renewable Energy Scheme.
Decide on the System
One early decision to make is the size of the system. This is a highly individual calculation based on a range of factors, including but not limited to: how much energy you use, how much energy a solar system can produce in your location, the orientation of your roof or ground-mounted array and how powerful your potential new solar panels are.
Many calculators exist online to help you determine the size of system that best fits your needs. The U.S. Department of Energy’s PVWatts Calculator is an especially fun one that calculates solar yield and can be used to determine how much energy a kW of solar panels will produce in your area. It is…detailed. Get ready.
You’ll also need to choose between a few different kinds of solar system readily available on the market today:
Photovoltaic (PV) Panels
PV panels are arrays of solar cells, which, with the help of an inverter, turn sunlight into usable electric current. With PV panels, you’ll face some choices about the kind of panels you want: monocrystalline, polycrystalline (or multi-crystalline) or thin-film.
Solar Magazine explains that monocrystalline panels, which are composed of wafers sliced “from a single silicon crystal” and arranged into grids, tend to be more expensive but also more efficient. Polycrystalline solar panels are constructed from “fragments of silicon” that have been melted and combined “before being cut into wafers.” They’re less efficient than monocrystalline panels, but they also cost less.
Thin-film solar panels can be made from a range of materials such as cadmium telluride (CdTe), amorphous silicon (a-Si) or copper indium gallium selenide (CIGS). The cost of these panels will depend on which materials they’re made of.
While they’re currently experiencing what Energysage calls an “efficiency lag” behind other types of panels, they’re expected to close that gap quickly. They’re currently best used by those with a big enough space to use a larger quantity of these panels to make up for their lower efficiency.
Solar roofing materials are an evolution of thin-film solar technology. They’ve seen an explosion of interest in the past 10 years, as they bring lower installation costs and a more low-profile aesthetic to the range of solar options.
Designed to mimic the look of traditional roofing materials, solar shingles, tiles or slates don’t need any supportive structure. They can be integrated into conventional roofing materials (even metal). They’re suitable for homes that can’t handle the extra weight of other kinds of solar systems.
On the down side, they’re still costly, can’t be tilted for maximum solar absorption and are less efficient than other kinds of solar systems. On the plus side, their durability makes them excellent as a roofing material. If you’re replacing the roof anyway, these might be a great option.
Solar Thermal Conversion
These systems have been used more for hot water heating than for generating electricity. More recently, though, they’ve been used to supplement conventional heating and cooling systems. They’re especially well-adapted for radiant floor heating and other kinds of liquid heating systems like radiators. They use solar thermal collectors to convert sunlight into heat. Heat transfer fluid circulates from the collectors to the existing HVAC or hot water system.
They’re much more efficient than PV systems and can be configured in a variety of ways, but this is a kind of solar system that’s currently lagging behind the PV industry. Interest in them is growing, however, as is interest in hybrid photovoltaic-thermal (PVT) systems. If your primary interest is in cutting your heating and cooling costs, this might be worthwhile to explore.
The other major decision you’ll need to make is whether to stay on the grid or go off-grid. Solar PV systems can feed into the grid, which might be more ideal if access to sunlight is seasonal or spotty in your area. They can also be entirely off-grid, which means you’ll need battery banks to store your energy. This will add a significant cost to the project, both up front and ongoing. Expect to replace the batteries every 5-10 years.
As with any big home upgrade, it will pay to do your research. Ask people who have had a solar system installed about their experiences. Or find forums online where people talk about the pros and cons of the brand of system they bought.
Once you have an idea of what you need, decide if you can install it yourself. If you have your system installed by a professional, get quotes from at least 3 suppliers.
When you vet your suppliers, research the quality of service they provide in addition to the quality of their products. You’ll want to be aware of the warranties they offer and their track record with customer service in case you need them down the road.