Questions about solar energy?

How can I use solar energy at my home, business or other building in Nova Scotia? How much does a solar hot water system cost? How much money will a solar water heater save? Are there rebates or incentives to install solar energy? What kinds of solar hot water systems are available in Nova Scotia? Can I heat my building with a solar water heater? What is an appropriately sized solar water heating system? How much does a solar air heating system cost?   How much solar energy do we get in Nova Scotia? Where can I install solar water heaters and solar air heaters?  Where can I order a solar energy system or get a price estimate? How can I use solar energy at my home, business or other building in Nova Scotia? i)     Passive Solar (Shelter Design): is a way of designing a new building (or major renovation) so that it naturally heats itself by the sun in winter and stays cool in the summer. In a well-designed passive solar building, most of the energy for space heating in winter is obtained from the solar radiation coming in through the windows, which saves you a lot on fuel. Solar Shelter Design is the most affordable way to use solar energy if you are building or renovating. Solar Nova Scotia sells the "Maritime Solar Shelter Manual" and offers a course on passive solar design. ii)     Solar Hot Water: A solar hot water system collects solar energy at your building to pre-heat water for domestic or service hot water and/or space heating. In many buildings, solar hot water can save a significant portion of your water heating bill. Here are examples of solar water heaters in Nova Scotia. iii)     Solar Air Heating: A solar air heating system collects solar radiation to heat air and circulates the heated air into your building. Solar air heating systems reduce winter heating bills substantially. Examples available in Nova Scotia include Cansolair and SolarSheat. If you know of other models available in Nova Scotia, contact us. iv)     Solar Photovoltaic (Electricity): Solar panels that generate electricity when exposed to sunlight. This electricity can be used for any purpose at your building, and it can either be stored in batteries until used (off-grid system), or traded with your electric utility (grid-connected system). How much does a solar hot water system cost? Depends on the size. The smallest unit is a one-panel system that typically costs between $5500 and $6500 (installed, before taxes and rebates), and serves up solar pre-heated water year-round for a family of two people. An extra $1000 can add a second panel to the same system, increasing the capacity for a family of three or more people. For systems larger than two panels, the total installed system cost is approximately $3000 to $4000 per panel, including all equipment (pump, heat exchanger, tank) and labour. Collectors vary in size, and this rough figure is based on panels that are 4 feet X 8 feet, and therefore have a surface area of about 3 square metres. How much money will a solar water heater save? A solar water heater in a household, if sized correctly, will save between 40% of 60% of the energy used to heat water for domestic uses. This typically translates to household savings of between $400 and $600 per year (at June 2008 energy prices), depending on the system size, the source of energy for your backup heater, and the amount of hot water used in your building. Are there rebates or incentives to install solar energy? Yes. Installing a solar water heater or solar air heater can qualify you for a 15% rebate of the pre-tax cost from the provincial government and in some cases a rebate from the federal government ($500 to participants in the ecoEnergy Home Retrofit process for homeowners, or a 25% rebate for qualifying commercial and institutional installations from the ecoEnergy Renewable Heat Initiative. What kinds of solar hot water systems are available in Nova Scotia? i)     Unglazed pool heaters (these are for summer-only use to heat pools). They are available through pool suppliers and some solar suppliers. ii)    Glazed Flat Plate Collectors – These are used to pre-heat water for domestic or service uses year-round, and can be applied to space heating. iii)   Evacuated Tube Collectors – These are used to pre-heat water for domestic or service uses or space heating year-round. NOTE: The year-round systems typically use a solution of antifreeze (non-toxic propylene glycol) in water as their heat transfer medium, to prevent freezing on winter nights. This is what allows them to operate year-round, and they can collect significant energy on sunny winter days. Price and Energy: The prices and energy output of these systems vary from one type to another and from one supplier to another. Your best bet is to contact several suppliers of systems for your application and obtain price estimates, but to ensure that the supplier also gives a credible estimate of the annual energy output of the system, so you can compare the cost per unit of energy delivered. Can I heat my building with a solar water heater? Yes, and there are several examples of people doing just that in Nova Scotia. Either glazed flat plate collectors or evacuated tube collectors can be used for space heating. You need more panels to do space heating than to do just domestic or service hot water. (For a household, typically four to ten panels, depending on the size and heating load of the building.) Include a backup heater in the system, which in some cases can be your existing heater. The design of a combined hot water / space heating system is a little more complicated than a simple solar water heater, so be sure you are confident in the details of how it is designed to work, or in the system designer/installer (for example, by asking for references from other clients using similar systems). A point to keep in mind is that in the Nova Scotia climate, if you have a system big enough to heat your building in winter then you will have excess solar heat in summer. In this situation, the panels will automatically shut down to prevent overheating. If possible, it’s a good idea to define a plan for how to deal with the excess heat in summer (use it for something or cover up some of the panels). What is an appropriately sized solar water heating system? See our Guide to Sizing a Solar Heating System. How much does a solar air heating system cost? For a typical one-panel solar air heater, installed on the wall of a house, the price in Nova Scotia ranges from $2800 to $3600 (June 2008 prices, installed, before taxes and rebates). As mentioned in A4, there are rebates available for these systems. Early estimates are that a single solar air heater panel can save around $500 to $800 per year on heating bills. How much solar energy do we get in Nova Scotia? On an annual average, Nova Scotia receives about 3.5 to 4 hours of bright overhead sunshine per day (this average takes into account winter, summer, cloudy days, etc.), which equates to approximately 1300 to 1500 kilowatt-hours (kWh) per square metre of available solar energy on an annual basis. Multiplying this number of kilowatt-hours by the collector efficiency (typically 0.5 for a solar water heater and 0.15 for solar photovoltaic panels) and the collector area, will give you a rough estimate of the amount of energy you can collect. For example, by this calculation a 4 foot by 8 foot solar water heater will collect approximately 2100 kWh of energy per year. Where can I install solar water heaters and solar air heaters?  Solar water heaters can be installed on a roof, a wall or a ground mount. The best direction for them to face in Nova Scotia is due south, although 20 degrees either way will make little difference. For year-round use, they are best mounted at an angle, up from the horizontal, about equal to the latitude, which is 45 degrees from the horizontal in Nova Scotia. If they are to be used only in winter for space heating, then a steeper tilt is better (anywhere from 55 to 90 degrees up from horizontal). If a south-facing wall is available, vertical mounting can be convenient and is fine for winter use, since the sun angle is quite low in winter. Solar air heaters, for example, are meant to be installed vertically on a wall as pictured here. If the mounting place is not at the desired tilt angle, the collectors can be mounted on metal frames at the desired tilt angle. Where can I order a solar energy system or get a price estimate? You are welcome to try our list of suppliers. We compiled this list by finding all the service providers we could and contacting them all to verify what they provide. We also asked them for two references from clients they have served. This list does not constitute an endorsement of any products or services, and the companies and organizations are not paying a fee to be on this list – we place it here for your information only. You have the sole discretion to decide whether or not to purchase products or services from any of the listed companies. If you have other questions, feel free to contact us.