How to set up solar power for your home: step one

The first step to going solar in your home is to do some really cheap things first.

— by The Solar Nerd — About a 14 minute read.

There’s a few reasons why people decide to go solar. You can save money. It generates electricity completely pollution free, and the full lifecycle pollution of solar (after accounting for manufacturing and the rest of the supply chain) is much lower than from any kind of fossil fuel. Generating your own electricity reduces your dependence on the utilities, which protects you from future price increases. And if you’re really intent on being completely independent, you can add batteries and be disconnected from the grid.

Even with all these compelling reasons to go solar, there are some things that are minimal effort and even free that you should do around your house before you make the major investment of adding solar panels to your roof. Some of these are obvious, but others are little vampires that you may not have realized are sucking energy and money out of your home.

After you’ve done these easy things to make your home more energy efficient, that’s when you should think about taking on bigger projects like solar.

So, in no particular order, here’s some tips to improve your home to efficient, and comfortable too:

Get an energy audit

An energy audit for your home is low cost - on average, a couple hundred dollars - or even free, because many utility companies have programs to help you reduce your energy usage. Check with your local utility for rebates. Those couple hundred dollars you’ll spend are a great investment because they will point out the most cost-efficient fixes and renovations for you to tackle.

An auditor will use an infrared sensor to assess the R-value (insulation levels) in your building envelope and let you know where air is leaking or your insulation could be upgraded. A more advanced test is a blower door test, in which the contractor shuts the doors and windows in your home, then temporarily inserts a special door that has a high volume fan that pumps air into your home, increasing the air pressure inside. (See photo above: credit Wikipedia.) The increased interior air pressure causes air to rush out of any gaps in your building envelope (such as cracks around your window). This makes it easy to identify the places where you can use weatherstripping, caulk, or spray foam to seal up those gaps.

Extremely cheap and effective air sealing

When most people think of air leaks they think of gaps around windows, especially if the windows are a little old and single pane. In fact, your windows are often not the biggest sources of air leaks. Instead, you want to pay a visit to your basement and your attic.

During the day, grab some toilet paper and go to your basement.

Your house sits on a foundation, and the part where the building meets the foundation is called the sill plate. Newer constructions should have a gasket or other sealant between the plate and foundation, but older homes may lack this. To find out, take a close look, and you may see daylight coming through. Even if you don’t see daylight, hold the toilet paper steady up to it and look for air movement. (Doing this on a windy day is even better.) Wherever you see daylight or air movement is a place where air is entering your home.

Air movement is not always easy to identify this way, and the materials to seal leaks are cheap, so it’s a good idea to run a bead of caulk regardless. If you discover large gaps, look to get a can of expanding foam. They come in different varieties, from minimally expanding foam for narrow gaps and more expansive foam for gaps up to a few inches. Anything larger requires more extensive repairs.

While you’re down there, take a look at your hot water pipes to see if they are insulated. If not, take a measurement of the diameter and buy the appropriate sized pipe insulation. It’s inexpensive, easy to install, and can make your mornings more pleasant by reducing the amount of time it takes for your shower to heat up.

Next, go up to your attic.

The first thing to understand is whether your attic is conditioned - meaning that it’s heated or cooled by your HVAC system and you have cathedral ceilings that are hopefully insulated - or unconditioned space, meaning that your attic is outside of the insulated building envelope.

If it’s unconditioned, hopefully there is insulation under your feet. What you are doing is looking for any type of penetrations from the ceiling below that go into the attic. These may be caused by electrical features such as recessed lights, junction boxes, and ducts for forced air HVAC, bathroom and kitchen exhaust fans. If it’s a loose insulation like cellulose or fiberglass batts, move it aside so that you can see how these features meet the basement floor.

Inspect the insulation around these features. If the insulation appears to be dirty, that’s a sure sign that you’ve discovered a place where air is moving, and depositing tell-tale dust and dirt. Use your can of spray foam or caulk to seal around these penetrations. If you discover larger holes, they may need to be patched with a material like plywood or drywall.

Important: If you find recessed lights, first determine what type of fixture it is before you replace any insulation around it. Modern recessed light housings are IC (insulation contact) rated, which means it’s safe to place insulation around them. Even better if they are also AT (air-tight) rated. If you find that yours is an older, unrated light, you should not place insulation around it and consider replacing it. A new recessed light housing is inexpensive, and those old ones can be major sources of air leakage.

By the way, if your insulation is vermiculite, leave it alone. Vermiculite is a natural mineral that often occurs next to asbestos, and absestos contamination was a problem with many vermiculite products. If you find this in your home, contact a professional asbestos contractor to have your material tested.

Photo of a vermiculite insulation
Example of vermiculate insulation. (Flickr)

While you’re up there, visually assess the amount of insulation. A visual check can’t tell you everything because air pockets may exist and be hard to identify. Still, you can take a quick measure of the depth of insulation in a few places to get an idea of whether you have nearly enough R-value.

The recommended minimum amount varies according to your climate, but if you’re dealing with loose fill insulation, it’s relatively cheap and easy to add more than the minimum, and it’s something that you can do yourself. We like blow-in cellulose because it’s non-toxic, uses recycled materials, and can be installed if you have a friend (one person feeds the hopper while the other operates the blower). Your local home center can rent you a blower. But fiberglass batts are also effective. Either way, attic insulation is relatively low cost and has a high return on investment.

Pay attention to the edges of the attic where the roof meets the floor. Soffit vents should not be covered to allow proper ventilation. Use a rafter vent over top of the soffit so that you can pack insulation up the soffit while still allowing air to move freely.

Seal those ducts

If you have a forced air HVAC system, an overlooked source of phantom energy loss is leaks in your ductwork. It doesn’t matter if the ductwork is within conditioned space or not: any leaks mean that your conditioned air is not going into the living spaces where it’s intended, and you’re losing money.

So, grab your toilet paper again (who knew toilet paper could save you so much money?) and go to your thermostat to manually turn the fan on. Hold the paper up to all the joints in your ductwork and look for air movement. Any places where you identify a leak can be easily sealed with either mastic - a tacky material that you spread over seams, reinforced with fiberglass tape for larger gaps - or UL181 rated foil-backed tape. Note that this isn’t the kind of cheap plastic tape that you might make a wallet out of or emergency flip flops. It’s a tape that is especially rated to hold up to high temperatures. Clean the surface of the duct before applying your sealing material. Choose mastic over tape, because the latter may not hold up as well over the years.

If you’ve found that your ducts don’t have any insulation, that’s another project with a high return on investment that a homeowner can tackle in an afternoon. Go to your home center and look for foil-backed insulation that is especially designed for ducts. There are types that are sized specifically for the standard duct diameters, so take some measurements before you go shopping.

Get a smart thermostat

Smart thermostats are so awesome that I’ve written a whole article about it. Not only do many utilities give you a substantial rebate (as much as $125 off in one case we’ve found) on the latest Wi-Fi models, such as those from Nest and Ecobee, many will actually pay you if you choose to participate in what are called demand management programs. With these programs, you can opt to allow the utility to modify your thermostat setting by one or two degrees during period of very high demand. Doing this lets the power company reduce peak power load during those periods of extremely high demand that strain the electrical grid or even cause brownouts, and you get paid a fee for a temperature change that you probably won’t notice. Win-win. Read more about smart thermostat rebates in your area.

LED lights

Are you really still using incandescent bulbs? You should switch to LED bulbs, which are about 90% more efficient than the 140 year-old technology of Thomas Edison. Unless you’re buying for specialized applications like your oven light or lighting for photography, there is really no reason to choose an incandescent bulb over LED. The prices have dropped dramtically - you can walk into your local home center and find bulbs as cheap as $1. And even though the upfront price may still be a little higher than a standard bulb, you will definitely save money in the long run with reduced electricity and replacement costs (they’re often warrantied for 20,000 hours or more). However, we recommend spending just a little more to get higher quality, especially because these bulbs last for many years, and if you end up buying a bulb you don’t like, you’ll either have to junk it or live with it until it burns out.

Example of an LED light bulb
LED bulbs don’t look weird. Waaaaay better than what Thomas Edison had to work with. [credit]

Spend a little extra for a high CRI bulb. CRI is a measure of the color accuracy of the bulb. Also, be sure to pick an appropriate color temperature for the room. If you want something that looks like a standard incandescent bulb, choose a warm white LED bulb, which will have a color temperature rating around 2,700 Kelvin. A daylight bulb, usually rated at 5,000 Kelvin, produces a stark white light that is appropriate for task lighting, such as a garage or security lights.

LED bulbs are available in all socket types now, including mini candelabra for chandeliers, and two-pin sockets common in track lighting. Check the review sites for the latest best brands, but I can personally vouch for Cree and Philips bulbs. Once I had a Cree bulb fail; after filling out an online warranty claim form, they sent me a new bulb even without a receipt. (No, they didn’t pay me to say that.)

Phantom loads

The average modern home is full of electronics: TVs, DVRs, cable boxes, network routers, computers, video game consoles. Even when these devices are switched off, they continue to operate in lower-power standby mode in order to perform useful functions. A DVR, for example, always needs power so that it can be ready to record your next episode of Jeopardy. Even something as seemingly low-tech as your coffee maker has a circuit board that runs the LCD display and internal clock so that your pot of coffee is ready in the morning.

With so many devices in the typical home, even if a single device draws as little as 5 watts in standby mode, a house full of these little energy vampires can have a noticeable impact on your electricity usage. And if you think about the fact that your neighbors homes are just like yours, you can quickly realize that the global impact of phantom energy can be significant.

This is why the One-Watt Initiative was proposed to limit new appliances from drawing no more than 1 Watt in standby mode. If enacted, the global CO2 reduction would be equivalent to taking 18 million cars off the road.

Older devices are less efficient, but the best way of identifying exactly how much power is being used is to buy an inexpensive energy meter such as the Kill-a-Watt. You plug the Kill-a-Watt into the power outlet, and the device to be measured into the Kill-a-Watt. It will give you an instantaneous reading of power, and also the average usage over time.

Example of a home energy monitor
Example of a home energy monitor. Good for killing Watts.

Let’s say your DVR draws 30 Watts in standby mode, which is pretty typical. Let’s do a little math to calculate the cost: 30 Watts consumed continously over 24 hours is 0.72 Watt-hours every day. Multiply that by 365 days a year, and you end up with 262.8 kilowatt hours consumed in a year. The average electricity cost in the US is $0.12/kWh, so that DVR may costs you $31.54 in electricity per year in standby power alone.

Maybe you think that’s not so bad, but that’s just one device. What if you have 10 of these little energy suckers in your house? How about 20? It adds up quickly. Get yourself an energy meter so that you can decide which devices can be unplugged or switched off with a power bar when not in use, or upgraded to a more efficient model.

Operate your shades

A surprising amount of heat energy can enter through your windows, and depending on the time of year, this can either be useful heat that you’re getting for free, or undesirable heating that causes your air conditioner to work harder in order to dump that heat back outside your house.

The Sustainable by Design website has a neat window heat gain calculator that can tell you how much energy enters through your windows for your climate in a typical year. If I put in my location as Buffalo, NY, it tells me that one square meter of south-facing window area (which is about equivalent to one of my double-hung windows) will receive 40 kilowatt hours of heat energy in the month of January.

Given that an electric space heater draws about 1,500 Watts at any point in time, this one window, if the shade was always left open during daylight hours, over the month of January would give the heating equivalent of running one space heater for more than one full day. If I’ve got five south facing windows of that size, that’s a lot of free heat for doing nothing but letting light into the house.

Example of a window heat gain chart
Example solar heat gain calculation for Buffalo, NY from susdesign.com

Conversely, in August, my solar heat gain through that one window rises to 53 kilowatt hours in August. But unlike in the winter, heat is something I do not want in my house, and those extra 52 kilowatt hours of heat will end up being removed by my air conditioner at extra cost.

So, in the summer, I should draw my blinds shut when I leave the house, because who cares if it’s dark in the house when nobody is home? This reduces the solar heat gain and saves my air conditioner from doing work. Best of all: this is free.

Bigger efficiency improvements

In this article, I wanted share a few things that I’ve found to be useful in my own home that are easy for the homeowner to do that give you a large return on investment.

The topic of energy improvements is really big, and a comprehensive review of the retrofits that a homeowner might do to make their home more energy efficient is outside the scope of this article. This is why getting an energy audit is a really good idea, especially if there is a rebate offered in your area. The report from a good auditor will give you a comprehensive summary of where your home is wasting energy, the easy DIY improvements that you can do yourself, and the more technical and difficult fixes that should be left to a professional.

Buying Solar For Your Home: The Complete Guide

This article is part of a series to help the homeowner go solar.