Home Solar Panels Cost, Financing & Installation
Solar Panels: A solar panel is a packaged, connected series of photovoltaic (solar) cells that generates electricity. Solar cells are typically made of silicon and use the photovoltaic effect to convert the energy of sunlight (photons) directly into direct current (DC) electricity. An inverter is then used to convert the DC power to AC (alternating current) power, which is the kind of power used by the electrical grid and almost all non-battery operated electrical devices (whatever you plug into the outlets in your home). Due to the relatively low efficiency of current cell technologies, each panel can only produce a small amount of power. Most installations require an array of panels.
Installing solar panels can decrease your household’s carbon footprint by an average of 35,180 pounds of carbon dioxide per year. You’d have to plant 88 trees every year to offset that amount of carbon dioxide!
Solar Panels on Home – Types, Benefits and Applications
Crystalline panels are the most common type of PV panel. The technology has been around for about 50 years and was first developed for powering satellites. They are capable of being up to 20% efficient. Most of these technologies are highly reliable (25 year warranties are common) and produce similar results in terms of output efficiency. The primary downsides of using crystalline are that they can be bulky, expensive, prone to damage, are rigid and require a lot of labor to install. That said, they are often the best choice for a residential solar energy system. They come in two varieties: monocrystalline and polycrystalline.
Monocrystalline silicon panels are made up of single-crystal wafer cells cut from continuous, cylindrical crystal ingots. They can be cut completely circular to minimize waste, but they are often trimmed into other, more square-like shapes (see below). Since each is made from a single crystal, the cells have a uniform, deep blue color. They are the most efficient units available today (they produce more power per square foot), but they cost more than other types.
Polycrystalline silicon panels are made of multi-crystal wafer cells cut from square ingots that are created by pouring molten silicon into a mold. This way they can be cut into square wafers to minimize waste. Each is made up of random crystal formations which make it various colors of blue (below). They are slightly less energy efficient, but also cheaper than monocrystalline.
Thin film modules are very inexpensive, but also quite inefficient (require more area per watt produced). Their efficiency is 10% or less and their long-term durability is often questioned. They are less expensive because they require less of the active material to function (below). In fact, they can be made microscopically thin, flexible and light weight and are deposited on a sheet of glass or metal instead of having to grow ingots and slice wafers. Cadmium telluride (CdTe) is the most cost effective thin film technology. Amorphous silicon is a material used to create panels that can be molded to the shape of almost any surface. Most of the research and development of solar cells is currently being focused on thin film technologies.
Building integrated photovoltaic (BIPV) panels look like an integral part of a roof since they are the same size and shape as shingles (below). They have lower efficiency and are more expensive than other panel types. They are most effective on large roofs in very sunny areas.
In the USA, a rule of thumb is that the average house consumes electricity at the rate of 1 kW per hour (kWh). There are about 730 hours in each month, and the average price of a kWh of electricity is $0.10. So an average monthly bill would be around $73 for 730 kWh of electricity.
The price of solar panels has dropped 60 percent since the beginning of 2011. Together with federal and local tax credits and subsidies, that’s helped drop the national average of up-front costs to about $17,000.
Local tax incentives vary by state and municipality. Los Angeles residents can take the ITC, then receive a property tax exemption from the state of California as well as a rebate of $0.12 per kilowatt-hour for 20 years from the city of L.A.
It’s worth doing your due diligence to make sure you’re taking advantage of all the financial help that’s available to you.
Trees, tall buildings, and even a chimney can all affect your panels’ sun exposure. And different kinds of panels react in various ways to shadow; some reduce output, and others shut down altogether. The more hours your panels are exposed to full sun, the more efficiently they’ll generate power.
Standard Solar System Components
This brings up an important point: it takes more than a solar panel to get a PV system up and running, though. The entire system is what drives the cost of solar up and equipment like batteries need to be replaced over time.
The good news is that the costs for solar panels are expected to continue to drop, as thin film panels from companies like First Solar, Nanosolar, and AVA Solar become available to the residential market and knowingmalta long term rental. Right now, though, First Solar is only selling to commercial customers. Nanosolar and AVA Solar have yet to ramp up their production facilities. It will be interesting to see where this all goes in the next year or two, since these companies are talking about very aggressive price targets — in the order of $1-2 per watt — and volumes that are several times today’s total output.
Assuming that installation and auxiliary equipment costs can be reduced to around $1 per watt, then a 5 kW system may cost as little as $10,000, and the payback period would be 10 years, even without subsidies. This makes PV solar installations much more attractive. Of course, all this assumes that electric rates stay constant.
However, they are likely to rise as fuel and other infrastructure costs increase, so payback periods may be even shorter in the future. In the meantime, expect to see more PV solar panels installed on roofs, especially in areas with favorable solar conditions or with higher-than-average electricity rates.