How does a Solar System work?

Solar energy takes advantage of the sun’s rays to generate heat or electricity. It is an infinitely renewable resource and unique for its ability to generate energy in a quiet, clean, and consistent manner. A photovoltaic cell, or “solar cell,” is the smallest semiconductor element that converts sunlight into electricity. Each cell is made of silicon or another semi-conductor material, like a computer chip. The silicon is treated so that it generates a flow of electricity when light shines on it.

Solar Cartoon

What are the components of a Solar System?

You will need a photovoltaic panel to capture the sun’s energy, a roof mount to support the PV panel, an inverter to convert the direct current (DC) produced from the photovoltaic cells into alternating current (AC) used by your home, and a house utility meter โ€“ called a net meter โ€“ that can record both the electricity produced from your home’s power system as well as any power you may use off the grid. These system components are then connected through a combiner box with series of wiring. The photovoltaic panels are secured to your roof with panel mounts or are installed on poles that can be adjusted for sun angle.

PhotoVoltaic (PV) Panel – Generates electricity from the suns rays.

Roof Mounting – Secures the PV panels to the roof.

inverter – Converts the PV DC into AC voltage for building use.

Combiner Box – Junction box to connect wiring between the PV cells, Inverter, Meter and Building.

Net Meter – Measures energy input from PV cells and measures energy being used or being returned to the power grid.

How much space do I need to install a solar system?

In bright sunlight, a square foot of a conventional photovoltaic panel will yield 10 watts of power. That’s a helpful rule of thumb for calculating a rough estimate of how much area you might need. For example, a 1000 watt system may need 100 โ€“ 200 square feet of area, depending on the type of PV module used. A 1,000,000 (megawatt) system may require 100,000 to 200,000 square feet.

Will I need a building permit to install a solar energy system?

Yes. You’ll need to obtain building permits to install a solar photovoltaic or solar hot water system. Similarly, building, electrical, and plumbing codes also apply. Solar power systems do not use “radical” building techniques and most jurisdictions have building codes that fully embrace solar energy technology.

How long will it take to install a solar system?

Planning, configuring, and doing any custom ordering for your solar energy system can take up to a few weeks.
The installation of a small residential system can typically be completed in a few days time. Larger commercial installations that require the engineering design and construction of extensive roof or ground support systems may take several weeks.

Can I use solar to heat my pool?

Yes. Pool heating systems can use a modified solar hot water system to capture the sun’s rays and heat your pool or hot tub.

Can I use solar to heat my home?

Yes. Solar can heat your home by using the solar energy to heat water, which is then transferred through pipes into an under floor radiant heating system. Radiant floor systems are typically 40 percent more efficient than their forced air counterpart and can be zoned to match thermal comfort to each room.

What maintenance does the solar system need?

The solar photovoltaic panels require little maintenance. No need to wash or dust. It is, however, important to place panels where they will remain clear of shade and debris. Thus you will have to wipe them off if too much snow or leaves fall on them.
Solar hot water collection arrays do not require much attention either. It does help to periodically use a window wash brush, biodegradable soap, and water to clean the tubes.

What is the difference between Solar PhotoVoltaic and Hot Water Systems?

While both types of solar systems capture energy from the sun, solar photovoltaic systems use photovoltaic panels to produce electricity. Solar hot water, or thermal, systems capture sunlight to heat water for domestic use, to heat a swimming pool, or for a radiant heating system.

What is the cost of a Solar System?

Solar Panels – As of 2015, solar panels cost approximately 80ยข per watt, which which is a sharp reduction from $3 per watt just three years ago. In addition, the solar panels themselves have improved from about 12% efficiency to over 18% efficiency. Therefore, the panels for a 5,000 watt system could cost $15,000 for a typical residence of 2,000 square feet. The addition of associated equipment such as panel mounts, inverters, and metering could cost approximately $1,000. Larger commercial installations would be sized according to KWH consumption and the available rooftop or ground level space for the installation of solar panels.

Federal Incentive Credits – Federal Tax Credits for solar systems signed into law on February 17th, 2009. This law provides a 30% nonrefundable energy tax credit for the cost of a qualified system through 2016. This includes solar electric (PV) systems, solar hot water heaters, geothermal heat pumps and wind turbines. When combined with state-level credits, it can dramatically reduce the cost of a solar PV system, sometimes by as much as 40-50%.

How much will I save with a Solar System?

Your savings will depend on the size of system you are installing vs. your average monthly use of kilowatt hours (KWH). It can be calculated in 6 steps:

Step 1: Calculate your average monthly cost for electricity.
Step 2: Calculate your average monthly use of KWH from your bills (Let’s assume it is 600 KWH)
Step 3: Calculate the maximum KWH generated by the solar system you have installed (assume your 4 kilowatt system generates electricity for 4.3 hours per day for 30 days). Maximum = 516 KWH
Step 4: Reduce the maximum generated KWH by 20% to arrive at a realistic contitions for rain and cloudy weather. Realistic = 412 KWH.
Step 5: Divide the realistic 412 kWH by the average of 600 KWH = 69%
Step 6: Multiply your average monthly bill by 69% to arrive at your savings. If you were paying $200 per month, you would save $138 per month, or $1,656 per year.

What kind of financing is available for Solar?

In addition to a cash purchase, you may consider:

Home equity financing – A home equity loan can be used for the purchase and installation costs of a solar photovoltaic or solar hot water system to take full advantage of federal tax deductions. Solar energy systems are also viewed as a major home energy savings upgrade and is comparable to other upgrades such as installing a new deck or remodeling a kitchen.

Lease purchase – Some vendors offer lease purchase financing with a large buyout discount after they have realized their tax benefit writeoffs.

Purchase Power Agreement – Some vendors will allow you to purchase the power directly from them through a purchase power agreement. The rates will be similar to the utility rates, but do offer a large buyout discount after the vendor has realized their tax benefit writeoffs.

What is the payback on a Solar investment?

You can calculate the payback in 4 steps:

Step 1: Determine initial annual savings from PV system. Let’s use the $1.656 per year from question 12.
Step 2: Assume a conservative electricity inflation rate of 4% increase per year for the next 25 years.
Step 3: Multiply the $1,656 annual savings by the energy inflation rate of 1.04 for each year over the next 25 years (the solar panels are warranted for 25 years). Cumulative savings is:

Year 5 = $8,968
Year 10 = $19,969
Year 15 = $33,244
Year 20 = $49,395
Year 25 = $69,106

Step 4: Subtract the initial cost from the accumulated savings – To see how you are paying off your initial investment

When should I not put in a solar system?

Poor Insulation – If your home is under insulated, there is no point in creating energy using solar panels only to have that very same energy go out through your roof and be wasted.

Old Roof – If your roof is on its last legs you probably should consider getting the roof done first so there is a good foundation for the solar panels.

Unavoidable Shade – Solar panels are very durable devices but their performance drops significantly if all or even part of the panel is exposed to direct shade for any length of time. If the shade cannot be removed effectively it will not be cost effective to install the solar.

Payback is Too Long – The payback period for solar energy may be too long. This is particularly true in those states that do not provide any incentives for solar energy. Any payback analysis should include an adjustment for the annual rise in energy costs. Some estimates used are 6% per year. Solar panels will last 25-30 years at minimum.