One of the first questions that we ask when a homeowner inquires about solar power is to see a copy of a recent energy bill. This is because we want you to see the maximum benefit from your investment in a solar electric system, and an analysis of your rooftop size, conditions such as shading, and your typical energy usage will tell us what can be realistically expected.
The number of solar panels needed to power a home or building does not depend on the size of the structure, because many different factors play into the overall energy usage. A large home with Energy Star appliances, replacement windows, and an energy efficient roof may use less electricity than a smaller home with drafty windows, a leaky roof, and old and outdated appliances. Even the habits of those living in the home affect energy use.
The fact is that your roof can only fit so many solar panels. If you have a lot of property, you may also be able to choose a pole mounted solar panel system in order to add more panels. However, an easier and more convenient choice would be to reduce your energy usage and live more efficiently, so that you can reduce the amount of electricity used, which means that your solar power system will need to produce less to keep up with demand.
A home energy audit will help you improve your energy efficiency by identifying the points in your home where electricity is wasted, and will provide you with the solutions to fix them. Reducing the amount of energy wasted will improve the benefit of a home solar system, and can help you save money, or even earn it, depending on the incentives available.
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Interested in upgrading your home to improve comfort, reduce energy costs and even boost long term home value? Montgomery County, using a grant from the U.S. Department of Energy, will be offering a one time program to help you pay for the costs of these improvements.
The Montgomery County Residential Energy Efficiency Rebate Program offers incentives to homeowners for energy efficiency improvements such as insulation, heating and cooling systems, and appliances. Owners of single family properties and condominiums can apply for up to $3,000 of funding per applicant. The minimum rebate size is $500 (typically a $2,000 to $3,000 project). The program is another example of how local governments are supporting the Maryland solar industry.
In order to be eligible, each applicant must have an energy audit from an auditor participating in the Maryland Home Performance with ENERGY STAR or a utility (e.g., Pepco, BG&E, Potomac Edison) audit program.
Homeowners are also encouraged to use these funds in concert with other incentives available from utilities, the Maryland Energy Administration and others.
Detailed information on the program, audit requirements, as well as links to other sources of funding is located on the website www.mcenergyfunding.com. Interested homeowners will also apply to the program online via the website. Real time information on the funding availability is posted on the program website.
Daylighting is the practice of using natural light to provide effective internal lighting. This method can be practiced through the use of strategically placed windows and reflective surfaces that would allow natural light to illuminate internally. Traditionally houses have more windows facing equatorial side rather than polar since sunlight occurrence is greater throughout the autumnal to spring equinox.
Some of the most popular types of daylighting include:
- Windows: you can improve lighting in a room by placing windows close to a light colored wall, slanting the sides of window openings so the inner opening is larger than the outer opening, and by using a large light colored window sill to project light into the room.
- Clerestory windows: high-vertically placed windows that are effective at reducing directionality of light to make it softer and more diffused, and to reduce shadows.
- Skylights: horizontal window, roof lantern, or oculus that is placed on the roof of a building.
- Light reflectors
- Light shelves: A white or reflective metal light shelf is placed outside the window. Usually the windows will be protected from direct summer season sun by a projecting eave. The light shelf projects beyond the shadow and reflects sunlight upward, inside, to illuminate the ceiling.
- Light tubes (solar tube): emits light to a focused area of the interior.
- Saw-tooth roof: vertical roof-angled glass that faces away from the equatorial side of a building and captures diffused light.
- Heliostats: mirrors that move automatically to continuously redirect sunlight in a constant direction as the sun moves across the sky.
- Smart glass: Glass that can be switched between a transparent state and a state which is opaque, translucent, reflective, or retro-reflective.
- Fiber-optic concrete wall: structural concrete walls that are embedded with optical fibers that allow daylight and shadow images to pass directly through the wall.
- Hybrid solar lighting: this design uses a roof-mounted light collector, large-diameter optical fiber, and modified efficient fluorescent lighting fixtures that have transparent rods connected to the optical fiber cables.
- Solarium, sunroom, greenhouse: normally large amounts of glass on the equatorial side of the building to let in maximum light during peak hours.
Daylighting is a cost effective alternative or great addition to installing a solar energy system in your home. And just like daylighting and windows, the placement of solar panels is important. Maryland solar energy is effected by the climate and positioning relative to the sun. Feel free to schedule an energy audit to see how solar energy installation team designs each system specifically for the homeowner.
Post written by: David Zamostny, Solar Energy World Intern
It is easy to flick a light switch, push the power button on the microwave, or get a cold soda out of the fridge. It is also easy to see how much total electricity you use per month. That comes on your bill, along with perhaps an ever-increasing price tag. But do you know how you are using all of the electricity? Or how much do everyday appliances cost you each year to run?
Have you ever went on vacation and left a standard 60 watt light bulb on for the week? That cost you $1.31 based on average Maryland-DC electricity costs.
How about your refrigerator? Well that depends on what model you have. Refrigerators from the late 80’s cost about $123.50 a year to power. For models from the 90’s and beyond, energy efficient refrigerators cost between $52 and $91 per year on average.
And what about that new 52” LCD Television? If you are the average household that has the TV running 5.2 hours a day, you run a yearly tab of around $42.
If you know how much your appliances cost to power, you can make better decisions about your energy consumption. You can see how upgrading to energy-efficient appliances can drastically cut your bill. Or, you might just think twice about using your appliances at the same frequency. For example, using a coffee maker to brew a pot of coffee a day will cost, on average, $3 a month. That’s $36 a year in electricity for your coffee– perhaps it’s time to try instant? Or, if you like all your gadgets, maybe it is time to schedule an energy audit and see how solar power can save you money while you enjoy all the benefits of technology.
For those that want to do some serious investigating, here is the formula you can use to calculate the costs of your appliances:
(wattage / 1000) x hours used per day x electricity cost = the appliance’s daily cost
The two things you will need to know is the wattage of the appliance and your electricity cost per kWh. Wattage can be found on the back, or inside, most appliances. If not, you can usually search online to find industry averages. For your electricity cost, you will want to consult your electricity bill.
For a 60 watt light bulb that was left on for a week:
60watts / 1000 = .06kWh
.06kWh x 24 hours = 1.44kWh to run the light bulb for a day.
1.44kWh x .13 (the average cost per kWh in Maryland-DC) = $.1872 per day
$.1872 per day x 7 days = $1.3104 per week to run a 60 watt light bulb.