Solar Electricity - Grid-Tied Solar Electric Power
Make Money & Your Own Power
Solar electric system installed on a home in Durham, New Hampshire
Grid-tied solar electricity allows you to generate your own electricity whenever the sun is out - locking in your electric rate and protecting you from the utility company's rate hikes.
Save Money and the Environment
57% of the electricity generated in the United States comes from coal-fired power plants, which are responsible for 93 percent of the sulfur dioxide, 80 percent of the nitrogen oxide emissions, and 73 percent of the carbon dioxide emitted into the atmosphere from electricity generators (Source: Power Scorecard).
Solar electric panels, in contrast, contain no moving parts and will generate electricity with no maintenance for 40-50 years.
Solar electricity is local electricity, meaning that power is generated where it is used and does not have to travel great distances over transmission lines. This is a more efficient use of electricity that reduces strain on the electric grid. When your solar electric system generates more power than you are using, it helps power your neighbors' homes!
How Does Grid-Tied Work?
Grid-tied means solar arrays which are connected to the electrical grid, as opposed to off-grid systems which run independently of the electric utility.
The beauty of a grid-tied system is that you essentially use the electric grid as a big battery - when you produce more than you need, you push power out to the grid. When you need more electricity than you are generating (for example at night), you simply draw power off the electrical grid as usual:
The key piece of equipment is the solar electric inverter which converts the Direct Current electricity generated by the solar electric panels into grid-compliant Alternating Current electricity used in your home.
Whenever you are producing more electricity than you need, the extra flows out to the grid and you get a credit from the utility which you can use against future electric bills - or, as will shortly be true in New Hampshire, your net generation will be available as a cash credit!
3.3 kilowatt Solar Grid-Tied PV Array at Yarmouth High School
In 2007, ReVision Energy partnered with Yarmouth High School to win a Maine-state grant to fund the school's first renewable energy system.
View Real-Time Output of this System Online
ReVision Energy LLC provides licensed and professional design and installation of Grid-tied PV systems and offers free quotes.
Why go Grid-Tied?
- Each Kilowatt of installed grid-tied solar power will produce roughly 1400 kilowatt hours of clean, renewable electricity per year in Maine.
- Each Kilowatt of installed grid tied PV will reduce carbon emissions by 1,700 pounds of CO2 per year, while also removing 2.6 pounds of sulfur dioxide and 1.4 pounds of nitrous oxide emissions.
- The technology is long lived: solar electric panels are warranteed for 25 years and are expected to last 40-50 with little to no maintenance.
- If everyone produced some solar power, collectively we would reduce and diversify our power consumption.
Aren't These Systems Expensive?
Solar electric systems have dropped considerably in price in the last few years. While they still are a significant investment, with current financial incentives and energy savings, the payback period is typically less than 15 years.
Current solar rebates include:
In Maine:
- 30% federal tax credit and $2,000 cash rebate for installing a solar electric system.
In New Hampshire:
- 30% federal tax credit and $6,000 cash rebate for installing a solar electric system.
If you look at purchasing solar panels as pre-buying your electricity for the next 25 years, you'll find that solar electricity actually costs less than grid power!
Consider the following:
| Costs: | Maine | New Hampshire |
| System size, in Kilowatts | 5 | 5 |
| Cost per installed kilowatt of Panels | $5,500 | $5,500 |
| Gross capital cost | $27,500.00 | $27,500.00 |
| Less: | Maine | New Hampshire |
| Federal Tax Credit Amount (30% of system cost) | $8,250 | $8,250 |
| State Rebate Amount | $2,000 | $6,000 |
| Net Capital cost | $17,250.00 | $13,250.00 |
| Effective Cost of Electricity | Maine | New Hampshire |
| Kw/hr produced Each Year | 6,750 | 6,750 |
| Cost of Electricity, Locked in for 25 Years | $0.102 kw/hr | $0.079 kw/hr |
| Savings, if Electricity is $0.16 kw/hr and stays that way for 25 years | $9,750 | $13,750 |
| Savings, if Electricity is $0.16 kw/hr today and increases by 2.5% every year for the next 25 years | $20,952 | $25,112 |
Even taking the conservative estimate of 25 years of system performance, for someone who can take advantage of the existing incentives, the average price per delivered kw/hr from a solar system is roughly half of what a kw/hr costs from the grid today!
Contact us for a free solar evaluation and customized project quote.
Other Frequently Asked Questions (Solar FAQ)
- Why should I install a Grid-Tied solar electric system on my house?
Grid-tied solar electricity offers a way to fix your electricity rate for as long as 50 years. The maintenance-free panels come with a 25-year warranty and the expected useful lifespan is double that. A grid-tied pv system can protect you from electricity price increases for decades. That's a feeling of energy security that is hard to duplicate. Many of our clients feel better knowing that they are producing their own electricity without any environmental harm - that they are part of the energy solution and no longer part of the problem. - How long will an installation take?
Our typical residential solar power job takes us about 40 hours of installation time on the roof, and about 10 hours inside the house. We typically send two technicians, so the job is usually completed in 2-3 days. - Will it pay for itself?
Grid-tied PV systems, with financial incentive programs, often have an economic payback period of less than 15 years at current electricity prices. As grid power becomes more expensive over time, the economic return on PV improves dramatically. With multi-billion dollar grid improvement projects already in place, the one certainty is rates on grid electricity will go up. - What are the incentives?
There is a federal tax credit of 30% the cost of the system, as well as local and state rebates. In Maine, there is a $2,000 cash rebate through Efficiency Maine, in New Hampshire the cash rebate is $6,000! - Does my roof need to face directly south?
In Maine, the optimal roof orientation is 196 degrees on the compass (known as 'solar south'), but the acceptable range is between 155 and 245 degrees. Within this range, power output stays within seven or eight percent of maximum. More important, however, is shading - we don't want to see any shading on a solar roof from 9 am to 3 pm, year-round. Even hardwood branches shading a portion of the panels in the winter will degrade the overall performance of the array. - Will the solar array put holes in my roof, or be too heavy?
We mount solar panels on a purpose-built aluminum rail system that is fastened about every six feet by penetrations into roof rafters. On a standing seam metal roof, these attachments are made directly to the standing seams, with no roof penetrations. On asphalt roofs, each mount is sealed with 50-year silicone sealant to prevent any leaks. We have not heard of a single leak as a result of PV mountings. As for the weight of the array, it is less than 5 pounds per square foot, so a typically framed roof is more than adequate to carry the weight. - How much roof space will I need?
Every kilowatt of solar array takes about 110 square feet. So a typical 2kw array will take a roof area about 8' high and 25' long. - What if my roof is not adequate?
We can also pole-mount photovoltaic panels, or ground-mount panels on a concrete base. - How will I know if the system is working?
All grid-tied systems include an inverter with a digital display of system performance. There are also advanced data monitoring options if you want greater flexibility. - Will the system be noisy?
Power inverters are relatively quiet - emitting about as much noise as a refrigerator. They are generally installed in utility rooms or basements where existing mechanical systems are, rather than living spaces. - Will I see a difference in my lights or in how appliances run, like on a generator?
Solar electricity is identical to grid power, so you will never notice that the house is running on solar power. What you will see, of course, is a smaller electric bill! - How much power will I be able to produce?
Each kilowatt watt of grid tied solar produces approximately 1,400 kw/hrs/year on a good solar site in Maine. - What happens when power goes out?
When the grid power goes down, the grid-tied solar electric system goes down, too. This is to prevent any accidental back-feeding of solar electricity to the grid which might endanger line-workers. While battery-based backup options exist, they typically add $10,000 - $12,000 of cost to a solar array. Due to the costs and un-eco properties of batteries, we recommend efficient generators for emergency backup. - What panels do you recommend?
We use a variety of top, well-respect solar panel manufacturers depending on the application. Among these we are a premier dealer for SunPower, who manufactures the most efficient photovoltaic modules on the market. This means you can get more solar electricity out of a smaller array footprint than you can from competing brands. SunPower is also the only manufacturer offering an 'all black' frame and panel design to mute the aesthetic impact of panels on asphalt roofs.
All reputable solar manufacturers offer a 25-year warranty on their panels, which are expected to live roughly twice that long. - What inverter do you recommend?
Again, we choose among a variety of top manufacturers depending on application. Among these are SunPower, SMA Sunnyboy, Fronius, and Enphase micro inverters. All inverter companies offer a 10-year warranty though the inverter is expected to last 25 years or longer.
