- 1. Solar Technology
- 2. System Design
- 3. Solar Products
- 4. Economics
- 5. System Installations
- 6. Misconceptions
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.
Photovoltaic cells are comprised of a semiconductor material, most commonly silicon. Adding common doping agents like phosphorous and boron, create conductivity within the cell and activate the movement of electrons. Doping each side of the crystal lattice in dissimilar elements attracts “free floating” electrons to one side, creating voltage potential.
Sunlight on photovoltaic modules produces direct current (DC) electricity, which is converted to alternating current (AC) by a device called an inverter, which is then wired into your main service module where it feeds your internal power grid.
The system is tied to the power grid (local electric power utility company). The solar power is added to the grid power, reducing the amount of power that must be purchased from the utility.
An off-grid solar energy system is where there is no connection to the utility company power grid. This type of installation requires a charge-controller, a bank of batteries and in most cases an inverter, so that electric power requirements can be met at night or during cloudy conditions.
There are various technolgies at different levels of development that is currently in the works in the industry. However, the most prevalent technolgies are listed below.
Monocrystalline – These are made from cells created by cutting thin slices from single crystal silicon block and are higher in efficiency, but also higher in cost per watt. They are easy to spot because they have a smooth even color, usually black.
Polycrystalline – These are made from cells created by cutting thin slices from polycrystal silicon block and are slightly lower in efficiency, but also lower in cost per watt. Polycrystalline silicon is the “chicken nugget” of silicon, made by combining many individual crystals. They are easy to spot because they have an uneven color, usually blue.
Thin film – These are made by depositing a thin layer of very finely powdered silicon (amorphous silicon) or other photovoltaic material, on a substrate. These are much lower in efficiency that crystalline cells, and somewhat cheaper per watt. They are a good choice for large ground mounted utility scale solar arrays where real estate is plentiful. Their low efficiency makes them undesirable for commercial and residential applications because they consume a large amount of roof space compared to mono or poly modules.
Solar modules are known to last 40 years or longer. Typical guarantees of a solar module include ten years workmanship and materials warranty and a 20-25 year performance warranty. The typical PV module performance warranty will guarantee 90% of rated production for 10-15 years, and 80% for 20-25 years. Solar modules are designed to withstand hail, severe wind and weather conditions assuming proper installation.
The technology used in commercial modules has been in production for over 20 years. Improvements have been gradual year over year. There are some promising developments in laboratory solar cells but nothing imminent that is deployable in real-world conditions.
The use of solar energy is growing rapidly, with global installed capacity increasing from 5 GW in 2005 to more than 140 GW in 2014, led by Germany, China and Italy. Capacity is doubling every 2.5 years, and has exceeded 300 GW by 2016.
Solar PV is a mature technology, and widespread adoption is happening because the price has fallen so dramatically. In 1980, a solar module cost $75 per watt. In 2014, it cost $0.75.
In 1998, the installed cost of household solar PV cost $11 per watt. By 2014, it had fallen to $3.50 to 4 per watt.
In 2014, a utility-scale solar installation costs as little as $1.50 a watt in Australia, Texas and California, which converts to a 30-year levelized cost of 9 cents kwh. In Ontario, the utility-scale price is $2.00 – $2.50 a watt.
In Canada, Ontario leads other provinces with 1,235 MW of installed solar PV in 2014 and 939 MW under development.
Ask for an estimate from a solar installer.
Typically the best return on investment is when you target the average power in watts used during the month with the lowest electric bill.
A typical solar module of 250W will measure about 17 square feet. Depending on installation factors, the required square footage of roof space will be somewhat larger than simply the area of the modules. Based on your information, once our engineering department has determined the required angle, shading factors, etc. we can give you a more accurate number.
Take a look at the position of your home on its lot and particularly your roof. Ask the following questions:
1. Is there good southern exposure? Orienting solar modules to the south maximizes the effectiveness of energy collection.
2. Is the exposure free of trees or buildings that could shade the modules or drop debris on them?
3. What is the pitch of your roof? Most roofs, from flat to 60-degrees can accommodate photovoltaic modules.
Absolutely, if you are good with roofs, tools and electrics. We always suggest our customer to get instruction from professionals. It will help you increase the production results. And more importantly, it will keep your system safe and sound.
No. There is no commanding reason why taxpayers money need be used to incentivize solar PV. However, with Vancouver commiting to reaching 100% renewable energy, we must further incentive the proliferation and supporting structures for solar in BC.
Net metering is an accounting method to accurately track electricity sent back to the grid. It allows utility customers who generate electricity on-site, usually from a solar PV rooftop system, to run their meter backward by sending the excess electricity generated back to the grid, or utility company. In turn, the utility company must pay the retail rate for the electricity sent back to the grid.
Yes. BC Hydro’s net metering program has been described as the best in Canada, both for its technical accuracy and for its simplicity. Fortis BC also offers net metering. Your solar installer will tell you what you need to know.