FAQ: How much more electricity will I use if I switch to an electric dryer or oven/stove?

Many people looking to go solar want to take full advantage of solar as a source of clean, low-cost energy. This includes “electrifying” their lives by switching from gas to electric clothes dryers or electric stoves and ovens.

Efficiency Vermont provides estimates for the amount of electricity used by different sorts of appliances. They estimate that electric clothes dryers and electric stoves each use approximately 900 kWh per year, in the typical home. For Green Mountain Power customers, as an example, that works out to about $11 more on the electric bill per month for each appliance. Read more

FAQ: How much more electricity will I use if I drive an electric car?

Driving an electric vehicle is an efficient way to get around, both in terms of energy and money. DriveElectricVT estimates that the cost to drive an electric vehicle—either all-electric or a plug-in hybrid—is equivalent to driving a gasoline car if gas is running at about $1 per gallon. And the cost for electricity is a lot more stable over time than the cost of gasoline.

If you are thinking about driving on electricity now or in the relatively near future, you may wonder about covering your electric vehicle’s needs with solar. The average American driver drives 13,476 miles per year, according to the Federal Highway Administration. An electric vehicle uses around 1/3rd of a kWh to drive 1 mile. That means to drive the average distance of 13,476 miles in a year, the car will go through 4,463 kWh. This is roughly 2/3rds to 3/4ths of the electric output of one Solaflect PV Tracker in Vermont or New Hampshire, depending on the Tracker’s location.

See more FAQs here, or quickly jump to electric use by heat pumps or household appliances.

FAQ: Can I mow under the Tracker?

Yes, you can mow under your Tracker. Your working space under the Tracker will depend on the time of day and day of year. That’s because the panels are tilted to face directly at the sun, and as the sun travels the tilt of the panels changes. As a result, the amount of space underneath the lowest edge of the panels changes.

When the Tracker is in the vertical position before sunrise and after sunset, the bottom edge of the panels is approximately 4 ft above the ground. You could easily mow under that with a push mower, but you’d risk collision if you were using a riding mower.

Of course, most mowing occurs during the day. On the Spring and Autumn equinoxes (on or about March and September 20th), the Tracker is tilted enough that the clearance beneath the panels is 5 ft or more from about 10:15 am through 3:45 pm. By Summer Solstice, you’ve got 5 ft or more of clearance from about 8:30 am through 5:15 pm.

See more FAQs here.

FAQ: How does solar production vary over the year?

Aka, take a ride on the Solar Coaster!

The amount of electricity generated by a PV Tracker varies greatly from month to month. Days in December (in Vermont and New Hampshire) are much shorter than in June. In December, each day lasts only about 9 hours. In June, each day lasts more than 15¼ hours, 70 percent longer than December’s day length. Read more

FAQ: Does northern New England get enough sunlight for solar to make sense?

The grass is always greener on the other side, and the sun always shines brighter in retirement states. Even so, Vermont and New Hampshire have no trouble sustaining healthy yards and pastures, and we easily get enough sunshine for solar to be a sensible choice for energy production.

Consider this map of the solar resource, created by the National Renewable Energy Lab: Read more

FAQ: What does solar do to property values and property taxes?

Many homeowners wonder what will happen to their home’s property value if they add solar. A number of studies have looked at this question. The largest and most thorough to date was conducted by the Lawrence Berkeley National Lab and published in January 2015. It looked at data from eight states over a fifteen year time period. On average, home values increased by $4 per watt of installed solar capacity. One Solaflect PV Tracker has 4 kW (4,000 watts) of capacity. See the report here.

Note that in Vermont, state law exempts solar equipment from being assessed for property taxation, so long as the solar array is smaller than 50 kW in size (that is, fewer than 13 Solaflect PV Trackers).

In New Hampshire, each town has the option to exempt solar from property taxation. Details regarding the towns that have adopted an exemption are available here. New Hampshire residents interested in solar should contact their local government to confirm the exact details for their town.

See more FAQs here.

FAQ: What are “Renewable Energy Certificates”?

Renewable Energy Certificates (RECs) are an accounting mechanism to make it possible to keep track of responsibility for bringing renewable energy to the grid. When one megawatt-hour (MWh) of electricity is generated from a renewable energy facility that is registered with the grid operator, a REC is issued to represent the renewable aspect of that energy.

Electricity on the grid is identical, whether it comes from a solar array or a coal-fired power plant. But we all know that energy from the sun has a different impact on the world than energy from burning coal. The REC represents that difference. It represents the reduction in soot, mercury, smog, acid rain, radiation, and carbon dioxide that we get from solar (or other renewable) energy as compared to traditional sources. Because we want a cleaner, healthier world, there is social value in the difference represented by the REC. Read more

FAQ: How large is a Tracker?

A Solaflect PV Tracker carries 16 solar panels. As a group, they cover an area of 20 feet wide by 12 feet high. The riser holds them up a few feet off the ground so that it won’t be a snow plow as it rotates in wintertime.

The space the Tracker takes up visually depends on the time of day and season. If it is vertical (for example before sunrise and after sunset) and facing directly at the viewer, it looks at its largest. Read more

FAQ: How do I compare a proposal from Solaflect with one from another solar installer?

The tradition in the solar industry is to compare system costs according to their “cost per watt” of capacity. “Capacity” is the ability of the solar panels to produce a certain amount of electricity when exposed to light. More specifically, it is a measure of how much electricity the panels will create when they are at a specific temperature and are exposed to light of a specific intensity. For example, a solar array rated at 4 kilowatts (kW) will produce 4 kW of direct current electricity under standardized conditions. The amount of electricity created by the panels will vary if the temperature or intensity of light change. Read more

FAQ: What is net metering? How does it work?

Net metering is a system of accounting on your electric bill to give you credit for the solar energy your system generates. The specifics can vary from state to state and from utility to utility.

Basic net metering works like this. First, think of a home that does not have a solar array. It gets all of its electricity from the utility. Whenever an electric device is on in the house, electricity is pulled in from the utility grid. The utility meter measures how much electricity is passed into the house. For each kWh passed into the house over the course of the month, the utility will charge a certain cost. Read more

FAQ: Will a Solaflect PV Tracker zero out my electric bill?

A Solaflect PV Tracker will produce a certain amount of electricity, based on its capacity (4 kW) [update: beginning Summer 2016, the Tracker has an increased capacity of 4.24 kW], how open the view of the sky is at its location, the time of year, and the weather during the billing period. We offer free site visits to assess the conditions at your property, including measurement of “solar access,” the term for how much of the sky the Tracker can see without trees, buildings, ridge lines, etc., in the way. A Tracker will be more productive in late spring and summer months when the days are longer, and less productive in late fall and winter months when days are shorter. (See “How does solar production vary over the year?“) As for weather, the sunniness or cloudiness of any particular month or year varies, and may change by 5% or 10% from year to year. Whenever we estimate production, we base that on the average conditions over the long term. Read more

FAQ: Will I get backup power from my Tracker if the utility grid is down?

Solaflect installs standard grid-connected systems. You will not get power from it when the utility grid is down. This is a National Electric Code safety feature built into the inverters. The inverter senses if the grid is operating normally. The moment the grid goes down, the inverter stops solar power from flowing through it. This is to prevent power backflowing into the grid where it might harm line crews that are fixing the grid.

For those who would like a degree of solar backup power when the grid is down, we offer an upgrade option to the SolarEdge StorEdge inverter. This inverter is fully compatible with the Tesla Powerwall battery system. We do not currently offer the Powerwall batteries directly, however with the StorEdge upgrade your Tracker system will be ready to “plug and play” with the Powerwall when it becomes more readily available.


See more FAQs here.

FAQ: What is Group Net Metering?

Group net metering means that more than one account with the utility can share the benefit of a single solar array. The specifics of how group net metering work depend on the laws and regulations of the state.

In Vermont, utilities are required to allow customers to use group net metering. All of the customers and the solar array have to be connected to the same utility. How the credit from the array is shared depends on specifics of the group arrangement. Read more

FAQ: What about future advances in solar technology?

Standard solar modules, which are based on crystal silicon, are 15-20% efficient. That means that 15-20% of the energy in the sunlight that lands on them is converted into electrical energy. The most efficient crystal silicon PV cell in the laboratory has achieved 25% efficiency. That record has hardly changed in the past 20 years. While manufacturing techniques have improved so that commercially available modules approach the laboratory maximum, and simultaneously lower costs, there is not all that much room for improvement in this most-common PV chemistry.

There are alternative PV technologies that achieve much better efficiencies, as seen in the National Renewable Energy Lab chart below. The panels that are in widespread use today rely on “Crystalline Si Cells,” specifically “Single crystal (non-concentrator)” and “Multicrystalline,” also without concentration. Read more

FAQ: What is the “solar adder”?

Vermont state law requires that utilities provide at least a minimum level of value for solar net metering. The way the law is put into effect depends on the utility involved and its rate structure.

If your utility is Green Mountain Power, then the solar adder functions as bonus credit on your electric bill for each kWh of solar you produce. You receive the solar adder for the first 10 years of your solar array. Read more

FAQ: What’s the difference between kW and kWh?

Let’s start with the terminology. A kilowatt (abbreviated as kW) is the same as 1,000 watts (or W). A kilowatt-hour (abbreviated as kWh) is the same as 1,000 watt-hours (or Wh).

A watt is a measure of the amount of power flowing at one moment in time. If a solar array has a capacity rating of 4 kW, then it is capable of putting out a flow of 4 kW of energy under the right conditions.

If that solar array produces at a rate of 4 kW for one hour of time, then it has created 4 kWh of energy. Read more

FAQ: What’s the situation with the Federal tax credit for solar?

The “Residential Renewable Energy Tax Credit” is a Federal income tax credit available worth 30% of the total cost of the solar array. This is available for solar installed for primary and secondary residences. For a Solaflect PV Tracker, this is worth nearly $6,000. The tax credit is available for solar installations that are in place and operating by the end of 2016. UPDATE: in December 2015, Congress extended the tax credit. It will be 30% through the end of 2019. After that the credit steps down over a few years. In the final year, 2021, the credit will be 22%.

Read more

FAQ: What happens to the Tracker when it is windy?

Solaflect PV Trackers include anemometers that are constantly measuring wind speed. If the wind speed gets high enough, the Tracker will “stow” in a horizontal orientation. By going flat, the Tracker presents only a thin edge to the wind, which can slide by easily.

Once the wind has calmed, the Tracker automatically returns to its normal orientation. While in the stowed position, the panels are facing upward. If this happens during daytime, they will still produce energy, even if not quite as much as when facing directly at the sun.

A Solaflect PV Tracker at dawn on a windy day.
A Solaflect PV Tracker at dawn on a windy day.

See more FAQs here.

FAQ: What is the process to learn if the Tracker will work at my home or business?

If you are curious about a Solaflect PV Tracker for your home or business, please contact us to schedule a free site evaluation. During a site visit we will answer any questions you have, assess solar conditions, review the condition of your circuit breaker, and check for other aspects such as the presence of ledge that may affect the Tracker’s installation.

The more sunlight that falls on the Tracker, the more productive it will be, and the more value you will receive from it. We use either a Solmetric SunEye or Solar Pathfinder to measure the “solar access” on your property. This is a measure of the percentage of open sky vs. trees/ridgelines/buildings/etc. that block sunlight at any particular location. More solar access means more sun for the Tracker. Read more

FAQ: How does the Tracker produce more energy? Part 3, shed snow automatically.

In Vermont and New Hampshire, snow is a regular part of life for a significant portion of the year. A solar panel with snow on it will not produce much, if any, energy.

If you have a fixed-mount solar array, you either need to be able to safely access your panels to brush them clean, or leave snow on them until it melts off by itself. Depending on the weather, this might take weeks to happen. Read more

FAQ: How does the Tracker produce more energy? Part 2, face directly at the sun.

Facing directly at the sun means receiving the maximum of the light’s energy. Sunlight falls on a fixed-mount solar array from an indirect angle at all times of the year except two moments. (The precise moments will depend on the tilt and orientation of the array. The ideal fixed-mount array will be perpendicular to the sun only at solar noon on the two equinoxes.) A seasonally adjusted array that has a different tilt for the summer and winter halves of the year will be perpendicular to the sun at only four moments.

Because of this indirect angle to the sun, some of the potential light is lost. Some passes by altogether, and some reflects off as glare. Read more

FAQ: How does the Tracker produce more energy? Part 1, longer days.

During the summer half of the year—from the day after the spring equinox to the day before the autumn equinox—the sun is rising out of the northeast and setting in the northwest (in the northern hemisphere). The “ideal” fixed-mount solar array is oriented due south, since that is the way that it will produce as much energy as it can. However, any time the sun is in the northern half of the sky, which occurs in the morning and afternoon for half of the year, the sun will then be behind the fixed array. Read more