How Solar Works
What is solar energy?
Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar energy technologies include solar heating, solar photovoltaic’s, and solar thermal electricity which can make considerable contributions to solving some of the most urgent problems the world now faces.
How do solar photovoltaic cells work?
In layperson terms, Photovoltaic’s is the direct conversion of light into electricity at the atomic level. Some materials exhibit a property known as the photoelectric effect that causes them to absorb photons of light and release electrons. When these free electrons are captured, electric current results that can be used as electricity.
What is the difference between mono-crystalline and poly-crystalline panels?
Mono-crystalline cells are made from a single crystal of ultra pure silicon. They are the original silicon solar cell and they are still the most efficient. Poly-crystalline cells are made up of multiple crystals and are generally cheaper to manufacture then mono cells. The gap in performance has narrowed significantly over the years to the point where they are very close. Both are good technologies, but mono cells tend to be more efficient but more expensive per watt.
What’s a typical solar panel efficiency rating?
Most solar panels are around 11-15% efficient. The efficiency rating measures what percentage of sunlight hitting a panel gets turned into electricity that you can use. The higher the efficiency, the less surface area you’ll need in your solar panels. Although the average percentage may sound a little low, you can easily outfit a typical roof with enough power to cover your energy needs.
What are the most efficient solar panels?
In the lab, scientists have developed solar panels that are 40% efficient, or even slightly more than that. But there’s a big difference between the lab and the real world. Manufacturers haven’t yet figured out how to take these experiments and produce economically viable products. Thinking you should wait for new whiz-bang panels is one of the most common solar myths.
Out of the solar panels on the market, SunPower makes some of the most efficient–one of their models is 19% efficient. They’ve reached that number by using several techniques, including a reflective coating that can capture more light from an angle. They also offer a line of panels that’s 18% efficient. Sanyo, another solar panel manufacturer, offers efficient models as well.
Should I choose the most efficient solar panels available?
High efficiency doesn’t mean better, it just means your panels use less space on your roof. Efficiency isn’t usually a critical concern unless you have an unusually small space for your solar panels. The most efficient solar panels cost a little more, so they’re a less common choice.
One Block Off the Grid’s pre-negotiated solar deals typically offer a choice of different recommended panels, including a more efficient panel for smaller spaces. If you have a normal amount of roof space to work with, you can focus more on the cost of the solar panels and the annual expected kilowatt production of your panels. We’ll help you choose the best panel for your particular needs and design a customized system around them. To request your free, no obligation system design and price quote, sign up here.
Getting the best power performance
In addition to efficiency and size, there are other factors that affect how much power your solar panels will generate. It’s important to make sure panels are installed in the optimal position, which is why you want to work with a highly experienced provider like One Block Off the Grid. The installers we work with will determine the correct orientation for your panels based on the direction and angle of your roof. They’ll also make sure the panels are installed with the proper amount of airflow so they stay cool– solar panels don’t like it too hot, and they’ll produce more power if they’re the right temperature. (To learn more, check out this article on how solar panels work.)
If you just go to the Big Box store and slap on a bunch of panels, you could end up wasting a lot of money. A high performing, long lasting solar array can incorporate dozens of factors in its design.
Factors that affect solar array efficiency include:
- Panel Orientation
In the U.S., your roof ideally should face south, but a quality design can often compensate for other directions.
- Roof and Panel Pitch
The "pitch" or tilt of your roof can affect the number of hours of sunlight you receive in an average day throughout the year. Large commercial systems have solar tracking systems that automatically follow the sun’s tilt through the day. These are expensive, however, and not typically used for residential solar installs.
Some panels like it hot but most don’t. So, panels typically need to be installed a few inches above the roof with enough air flow to cool them down. Some photovoltaic panels are designed to be more efficient in hotter climates. Check out the solar panels used by San Antonio and Phoenix home owners.
Basically, shade is the enemy of solar power. With poor solar design, even a little shade on one panel can shut down energy production on all of your other panels (like a bad bulb in a string of Christmas lights). Before we design a system for your home, we’ll conduct a detailed shading analysis of your roof to reveal its patterns of shade and sunlight throughout the year. Then, our local installation partner conducts another detailed analysis to verify our findings. This is just one of many reasons to work with a highly experienced solar provider like One Block Off the Grid.
How much maintenance do solar energy panels require?
Solar photovoltaic panels require little to no maintenance – there is little need to wash them as a good rainstorm will do that naturally here in Ontario. It is, however, important to place panels where they will remain clear of shade and debris.
Should I wait for upcoming breakthroughs in Solar technology?
It may come as a surprise to many people but solar photovoltaic cells are not new. They were first discovered in 1839. There have been many breakthroughs since then but the advancements are getting smaller. In Europe, large solar plants cover 1000’s of acres and have for years. There may be a company or university that claim to be on the verge of a breakthrough but there always will be. If you put money down on a solar system today, your ROI will be the same today as tomorrow, a year from now, or ten years from now. Advancement in technology or price in the future will never mean you’ve made a bad investment today in solar technology.
Should I wait for panel pricing to come down in price?
This may be a difficult concept to grasp, but if the price of solar panels were less right now then small generators like homeowners would actually make less money. Let me explain: The government has set the Feed-In Tariff price at a level that they believe will cover costs and provide a reasonable rate of return. One of the biggest factors when setting this price is the price of solar panels. If panels were to cost half as much as they do now then the Feed-In Tariff would probably be about half of what is offered today . Sure, we could install twice as many panels for the same price and same return but most of us do not have unlimited roof space and even if we did, there would still be the 10kW limit.
The second part of this answer is a little easier to understand. The price of panels (internationally) has dropped drastically over the past couple years but this has little to do with technology. Due to the global credit crisis, there have been many large cancellations which have led to a temporary oversupply in the market. We would actually expect the price of panels to slowly rise in the near future if the financial world works out its problems.
Solar and Batteries
When some people think about solar, they might think that they will become free from "The Man," because a battery will allow them to store any excess power they generate, thus taking them off the grid. While this is possible with solar, it doesn’t make much financial sense for most people. Allow us to explain:
- Grid Tie Solar
Most solar systems are "grid tied" these days. That means when the system is generating power during the day, any excess power it makes is fed back into the grid through something called "net metering." Your meter spins backwards and the utility credits you for that power. At night or on overcast days, you’ll use grid power instead of solar, but your utility doesn’t charge you until you’ve used up all the credit you generated through your panels. More on grid tie solar.
- It Means You Probably Don’t Need Batteries
You don’t need batteries for your solar system if you’re already connected to the grid. It’s an option, but not one that most people use these days because the batteries are still very big and bulky. They’re also expensive and need to be replaced every five to ten years, depending on the type and how well you take care of them. Battery technology is evolving and solar batteries may become a more viable option someday, but for most people right now, it’s more practical to simply tap the grid in off hours.
- Net metering – The Virtual Battery
Net metering is like a virtual battery. The utility keeps track of any extra power your solar panels produce, which spins your electric meter backwards. Then at night, you simply use grid power on the credit you earned while supplying the utility company with power during the day. Net metering is maintenance-free and typically costs around $5 per month in administrative fees.
- What about 'One Block Off the Grid’?
It’s true, our name has "off the grid" in it. It’s just a metaphor. We want to take at least one block’s worth of grid energy usage out of every city per campaign, but the bottom line is that we’re here to help you buy solar panels for your home.
- The Truth about Solar Batteries and Back-up Systems
We understand that some people are interested in solar batteries in the interest of disaster preparedness, and because this is America, you’re free to spend your hard earned money any way you want. Here are a few things to consider in your decision though:
- Battery back-up systems are reliable for those "what-if situations."
• However, those "what-if" situations are fairly rare. The American electric grid is over 99% reliable, and using a battery would mean you’d be spending an extra $7,000 to $15,000 every 10 years for the 1% chance that you will need battery back up.
• Also, disasters that upset the grid are typically repaired within days. There are, of course, exceptions like Hurricane Katrina…..but:
• It would most likely be more cost effective to spend money on flashlights, candles, matches, batteries, extra blankets, and dry good food, water, radio, etc, and be without the modern conveniences for a few days than it would be to purchase an expensive battery. Even in Hurricane Katrina’s case, your entire roof could have been blown away and/or your battery system under water and ruined. Same for an earthquake. Having a battery back up system may not be so important if the rest of your house is unlivable.
• Bottom line: Battery back-up systems do work, but they’re expensive for the few times they’re needed. It’s more cost effective to prepare to live for a few days without electricity until power is restored.
Will Solar increase the value of my home?
The National Bureau of Economic Research (NBER) in the U.S recently released an analysis that found solar panels add between 3 percent and 4 percent to the value of a home. That result is consistent with a study released in April by Lawrence Berkeley National Laboratory which found that solar photovoltaic (PV) panels have a "sizeable effect" on home prices. See http://news.cnet.com/8301-11128_3-20088646-54/econ-101-solar-panels-increase-home-values/
Designing Your Solar System
How do I know if my house is a good candidate for Solar?
We can definitely help with that. Before installing Solar on anyone’s home or business, we first conduct an inspection of the property either through satellite imagery (first) or in person.
Here’s what we’re looking for:
- Is there good Southern, Western or Eastern exposure (although south is best, east and West roofs can still be very rewarding)?
- What is the pitch of the roof (25-50 degrees is typically optimal)?
- Are there any shade considerations to avoid? (trees, chimneys, plumbing stacks)
Our Solar inspectors have specialized tools to perform a shading analysis to determine if shading will be a problem for your site. Cutting back trees may be a solution and we will advise accordingly.
After determining the size of the best system for you, we can then determine your systems estimated production in kilowatt hour ’s (kWh’s) based on your roof pitch, azimuth, and shading and provide you with an fairly accurate projected return on investment. Once you have a sense of how much energy your system will generate, you can evaluate the cost of purchasing.
Installing systems smaller than 2kW may not be worth your while. If you’re trying to do the math yourself, then figure each panel as is about 5.5 feet tall by 3.3 feet wide. We mainly install in a portrait orientation, but occasionally in landscape if it makes sense to do so.
How much space do I need on my roof?
In bright sunlight, a square foot of a conventional photovoltaic panel will yield 15 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 50 – 100 square feet of area, depending on the type of PV module used.
How does shading affect my solar panels?
Unfortunately shading your Solar system can dramatically decrease its output. Just shading the bottom row of cells alone could amount to up to 80% reduction in its efficiency.
Will my roof handle the weight of these solar panels?
Very likely, however if required, we will consult with an engineer to ensure it does. The weight of the solar panels and mounting system adds about 3 pounds per square foot, which is pretty low when you think about it. It would be like adding another layer of shingles on your roof.
Will installing Solar potentially damage my roof?
We use the utmost care when adhering the racking onto your roof. We will be sure to use the appropriate mounting systems that will work with pretty much every type of roof being used in Ontario. While we will penetrate into your roof to secure the racking to the frame underneath, we take great care to ensure we don’t introduce any potential leaks and warranty against this.
What if my shingles are not in very good condition?
We typically suggest that if your current roof shingles are worn, that you replace them first. Remember that your Solar system will remain on your roof for 20+ years. If you have to pull the panels off so that you can replace your shingles, it will be at your expense. If you can’t afford to re-do your entire roof right now, then see if you can just do the area where the panels will sit.
How does snow affect the panels?
We live in a climate where snow is a yearly visitor. There will be times during the winter months when snow will accumulate on the panels from time to time. In most cases, the panels should be mounted at an angle so snow should slide off or melt away on a sunny day. Not to worry though as these factors should be accounted for when we provide you with your kWh production estimates.
Will small animals or birds be a problem?
Unlikely, as they don’t like the extra heat during the summer months. However, you should inspect your panels at least once a year to see if this becomes an issue. If this becomes an issue, please notify us and we’ll do our best to come up with a solution.
Is wind and/or hail something I need to worry about?
Yes, it’s a design consideration and we engineer your system with wind considerations in mind. While hail certainly could damage some types of solar panels, the likelihood is very small and occurrences are extremely rare. Many solar-electric modules are made with tempered glass and under standard test conditions they will withstand hail up to one inch in diameter, traveling at 50 miles per hour.
Will my house be powered by this new electricity I’m generating?
Yes, but indirectly. 100% of the power you generate goes straight to the Grid, then likely right back in to your house and then your neighbour’s houses. 100% of the power goes to the grid to maximize your revenue which works in your best interest.
Installation Of Your System
What are the main components of my Solar system?
Your Solar system will be comprised of a number of solar modules to capture the sun’s energy, an inverter or micro-inverters to convert the direct current (DC) produced from the photovoltaic cells into alternating current (AC) used by your home, and a new export meter which will record the power being generated
These three primary system components are then connected through a series of wiring. The photovoltaic panels are secured to your roof with racking or in rural areas, installed typically on a ground mount structure that can be adjusted for the best sun angle.
What’s the difference between a string inverter and micro-inverter?
First off, let me tell you that this is a very controversial issue in the world of Solar as some people absolutely love using micro-inverters while others are devoted to string inverters.
The inverter is the main component of the transmission process and it’s purpose is to convert the electricity your array generates from Direct Current (DC) to Alternating Current (AC) which is what we use in our homes and businesses.
First, it goes without saying, that the inverter needs to be chosen carefully. To install the best one, you need to consider the size of the PV array, the type of modules, orientation and pitch of the roof, location and potential shading problems. We’ll help you choose what works best based on your application.
A micro inverter is a compact unit, installed at the back of each solar module. It converts DC to AC power for each module individually.
With a string inverter configuration, the PV modules are wired in a series very similar to Christmas lights. On a residential installation, there are usually two to four "strings" of modules wired in a series.
It’s the inverter’s job to try and track the maximum power point, but it can only recognize a string of panels, it doesn’t know which panels are doing what.
How long does it take to install?
The installation process itself can typically be completed in only a few days time, in many cases even less. Factors to consider will be the size of the installation, and the complexity of your roof, however, we can usually get it completed anywhere from 2 days to a week.
How long will my Solar system last?
Most Solar panel manufacturer’s warranty their modules for 25 years. Inverters have warranties of 10-25 years depending on the manufacturer. Solar panels should actually last about 30-40 years. Your contract with the OPA will run for 20 years. Remember, your panels should still be operating well past your 20 year contract with the OPA which means you’ll have some additional benefits at the time.
Will I require batteries for my solar panels?
Typically not – a backup battery bank can add as much as 30% in cost to a residential solar PV system. It’s not necessarily more efficient either – a same sized solar array can yield about 7–10% less energy if it’s battery-tied than its grid-tied counterpart.
Though you will remain grid-tied to your local utilities’ grid, you will not have to worry about not generating enough power. Most solar photovoltaic experts do not recommend installing an "off grid" battery system unless the residence is in a remote location without the availability of Hydro.
Will I have electricity when the power goes off?
As a safety precaution for hydro workers potentially working on the lines, the answer is no. It also gets more complex (and expensive) to install a battery backup option. When the power does go out, it’s typically not for long periods of time.
Will I require a new meter?
Yes, a new meter will be installed. The new meter monitors electricity going out to the grid so you can get paid. Your current meter monitors electricity coming into the property so your Hydro provider can charge you.
Would it be better to use the electricity in my house and then send extra electricity to the grid?
Absolutely not and here’s why. If you look at your hydro bill, you’ll see that you buy your electricity at a rate of about 7-10 cents per kWh (depending on the time of day). Under the microFIT program, generating electricity with solar power and selling it to the grid will pay you a premium rate per kWh (see current microFIT rates).
It will work out better for you to sell all of your electricity at the premium per kWh rate to your hydro provider and then buy it back at your current rate of about 7-10c/kWh. That’s it in a nutshell. You’ll also pay off your system much faster buy selling all of your electricity that your system generates to your hydro provider.
Will I need a building permit to install a solar energy system in my home?
This all depends on where you live. We’ll check to see if a building permit is required to install a solar photovoltaic system at your home or business. That said, residential solar power systems do not use "radical" building techniques and most jurisdictions have building codes that fully embrace solar energy technology. We include permit fees for permits into your cost estimate.
How much does a solar electric power system cost?
This question is a little tricky because it depends on a number of factors, namely how many panels you can fit on your roof, the type of panels you choose and the type of inverters used. The price of panels fluctuates often so we suggest that you contact us and we’ll work it out based on your particular installation. We can tell you that we include the following components in all of our installation - solar panels, panel mounts, and inverter(s), permits (if required), design, engineering, electrical and labour associated with installation.
Under the current micro-FIT rules, you are allowed to install up to 10 kW’s of Solar.
What costs are not included?
You can expect your hydro provider to charge you a one-time "New Meter" connection fee to install your at your home. This cost varies per Hydro company so ask your installer what this cost will be to you. Also, your Hydro provider will charge you a monthly fee of about $5.25 per month to read the new meter.
Do I need special insurance requirements?
Standard homeowner’s insurance policies usually suffice to meet electric utility requirements. Many companies have quoted our customers anywhere from $0 to $200 extra per year depending on the size of their systems.
Other companies have taken the approach that since this equipment is earning revenue, it should be classified as commercial which automatically puts you in the $1,000 to $2,000 range.
Most insurance companies fall into the first group. They generally have some limit on how much you can earn a year before they consider you a commercial setup. Check with your insurance company. In some cases our customers have had to change insurance companies to get reasonable rates. It won’t take long before all insurance companies are charging reasonable rates for solar equipment.
How much money can I expect to make each month?
Your payments will be dependent on the size of your system, the pitch of your roof and any shade considerations. Your cheques will typically be larger in the summer months (longer days, more sunlight) and less in the winter months. The average household can expect to earn approximately 10% return on your investment each year of your 20 year contract with the OPA. We’ll provide you with a realistic estimate based on actual conditions for your home or business.
Who pays me for my electricity?
Your payments come directly to you from your local Hydro Provider either by cheque or direct deposit.
Who is my contract with?
Your contract is with the Ontario Power Authority which is the pseudo-government organization that regulates electricity in Ontario. The OPA has a mandate to ensure a reliable, sustainable supply of electricity for Ontario. While the OPA is not strictly a government agency their directors are appointed by the Minister of Energy.
Can I trust the OPA to honour my 20 year agreement?
The credit worthiness of the OPA (Ontario Power Authority) derives from the fact that it has the authority to recover all its costs from Ontario electrical customers through uplift charges. So basically they can’t go broke since they have a monopoly on the sale of electricity in Ontario and they have the right to charge whatever they need to.
Their credit rating is AA1 which is the second highest available. Currently, only five US corporations hold a higher credit rating then the Ontario Power Authority, GE and IBM only have an Aa2 rating. The stocks and funds that your RRSP are invested in probably represent a higher risk of defaulting than a contract with the OPA.
Your Micro-FIT or FIT agreement is a legally binding contract that is enforceable in court.
What if I sell my house?
The OPA anticipates that sellers would include their renewable energy systems as part of the sale of their homes. In this case, the microFIT contract can be assigned to the purchaser. The new contract holder would receive payments in accordance with the microFIT contract for the remainder of the contract term. Should you wish to take the system with you, the contract would need to be terminated and you would have to re-apply at the new address. It may also be possible for you to work out a lease or rental agreement with the new owners and continue to receive the income.
Am I required to register a business?
No, and in some cases, it may disqualify you from the micro-FIT program. You can simply declare it as "income" on your personal tax submission. HST only needs to be charged if you are earning more than $30,000 in a business venture. Please consult the OPA Eligible Precipitant Schedule to see how and if you would qualify. http://microfit.powerauthority.on.ca/new-criteria-developed-better-define-microfit-program-eligibility
Can I finance the cost of my system?
Certainly, most people do just that. Consider using a home equity loan for the purchase and installation costs of your solar photovoltaic system or talk to your installer about financing options. Solar energy systems are viewed as a major home energy savings upgrade. Banks view it similarly as installing a new deck or remodelling a kitchen with the distinction of you receiving money back each month for your investment.
Are there any tax breaks for the income that I receive from my Solar system?
This is really a question for your accountant but we will give you some ideas for you to discuss with him or her.
- Until your system is completely paid off you will not need to pay taxes on the income. Solar PV systems, including equipment and labour falls under Class 43.2 of the tax code and are subject to a 50% depreciation rate on a declining balance.
- You may apply any costs that you incur in owning your system against the income. This would include additional insurance and interest payments if you finance the cost of the system. In the case of ground mounted system, you may be able to claim a portion of your property tax bill since they are taking up space on your property.
- You may be able to claim the income in the name of the lowest income earner, your 3 year old probably isn’t going to qualify but a stay-at-home parent may be able to claim the income almost tax free.
Once again, you should discuss this with your accountant but at the very least you do not need to worry about paying taxes for at least the first seven years.
Can I receive the HST back from the cost of my system?
In many cases yes, you can apply to get the full amount of HST back from the cost of your system. Please talk to your accountant or and check out the following link to find out how. http://www.cra-arc.gc.ca/E/pub/gi/gi-122/gi-122-e.pdf
Where should I go for financing my system?
Typically after we determine the cost of your particular system, we ask that you first check with your local bank to get the best interest rate from a secured Line Of Credit
We can also provide you with financing options although your own bank will probably provide you with the best rate, typically prime plus 1 or 2 points. The bank understands that you’re getting a guaranteed income from the Ontario Government for the next 20 years.
Are there areas of the Province where capacity to the grid is an issue?
Yes, which is why after submitting your OPA application, we will also check with your local hydro Provider to also determine that there is enough capacity in your area to proceed with your project. If not, we will do our best to keep your file active until the time comes when there is capacity.
How Solar Affects Our Environment
How much energy is used to manufacture a solar panel?
Data from the Energy Environment and Economics Inc. showed that the average solar panel gets five times more energy out than was originally put in.
See http://www.solarbus.org/documents/pvpayback.pdf for more details
Does the manufacturing of solar panels release greenhouse gases?
Solar energy has long been touted as better for the environment than fossil fuels. Scientists have studied the matter closely and now conclude that manufacturing Solar cells produces far fewer air pollutants than conventional fossil-fuel-burning power plants.
See http://www.livescience.com/2324-solar-power-greenhouse-emissions-measured.html for further details.
Will generating solar power reduce the use of nuclear power in Ontario?
Probably not, but it will reduce our use of coal. The output of nuclear power stations is not adjustable. They are always running at the same rate. If there is excess power required, they throttle back the coal generation first, especially during peak times (Summer when air conditioners are roaring) which is why Solar is so valuable. Solar works at its optimal performance during these peak times.
Does it make sense to trim or cut down trees that might shade my solar array? Don’t trees help reduce global warming?
Trees reduce carbon in the atmosphere by building plant tissue out of it and locking the carbon away. Unfortunately this is only temporary, when the tree dies and is burned or rots; the carbon is released back into the atmosphere. Solar panels reduce carbon in the atmosphere permanently by generating power that would have been generated by coal.
Let’s put it into perspective. An average tree in the Canadian climate will temporarily reduce carbon in the atmosphere at the rate of about 20kgs of carbon per year. An average 10Kw solar array will permanently reduce the amount of carbon in the atmosphere by about 15,000kgs per year.