Today, many homeowners around the world are considering moving away from the fossil-fuel based energy sources that have served as our primary sources of electricity for the last 100 years or so. Using renewable energy sources for home living is simpler and less expensive than you might think. With the growing awareness of climate change and the diminution of nonrenewable resources, attention has shifted toward finding sustainable technologies and re-thinking age-old solutions for economy and efficiency.
If you are in the stage of building a new home, a careful analysis of needs and expenses can save you a significant amount of money and wasted energy over time. The United States Department of Energy website has tools to help you calculate your energy needs so that you can decide what systems work best for you. It recommends a lot of common-sense considerations, such as designing for light and temperature that one might not otherwise think about.
In addition to evaluating your electricity use, it is important to look at local codes and requirements to determine the technology options for your site. Tax credits may also be available for energy-efficient investments and the Department of Energy website guides you through the criteria .
Maybe you are considering purchasing a renewable energy system to generate electricity at your home. Feel good about the time spent researching your options. Using solar energy rather than relying on power generated by nonrenewable fossil fuels, lessens your carbon footprint on the earth. And you also become independent of the uncertainties and costs associated with the import of foreign oil to meet our energy needs. Renewables allow us to develop locally sourced power for our own communities.
Generating electricity at home from renewable sources of energy
While renewable energy is going to be a key factor in gaining your independence from fossil fuels and it is tempting to implement these things first, you should first examine your existing energy use and find ways to increase the energy efficiency of your home where possible. By going after the sources of energy losses first, you will maximize the total energy efficiency of your home once you decide to start using renewable energy sources.
The first step in this process would likely mean having an energy audit done on your home to determine where all of the energy waste lies. Most important is the “envelope” of your home, where you can have many energy leaks, such as through inefficient windows and doors, and insufficient insulation in your walls and your attic.
Next, you should take a look at all of the appliances in your home to make sure that they are efficient. Appliance standards such as the Energy Star program in the United States help consumers to determine what the best choices are when it comes to energy efficient appliances.
Another priority is installing a programmable thermostat in your home to reduce your heating and cooling energy use when you are not at home or when your household is asleep for the night.
Other home improvements that can help to increase energy efficiency include maximizing passive solar energy in your home. This can be done by the use of skylighting or other daylighting systems that bring natural daylight into your home and reduce the use of artificial lighting.
And, of course, you must work on your own energy use behaviors and maximize energy efficiencies there. It is easy and free to turn off lights and home electronics when not in use, putting electronics such as our computers in sleep- or energy-saving mode, and using energy-efficient lighting such as LED light bulbs will also help to reduce our energy use (don’t forget to turn off your computer monitor when you aren’t using it!).
If you are building an entirely new home, you could also consider building one that requires very little energy use in the first place, such as through a Passivhaus design.
Implementation of renewable energy to power your house
After making your home as energy efficient as possible, the next step is to add some sort of renewable energy system to reduce or eliminate your need to use electricity sourced from the electrical grid.
Before choosing which renewable energy technology to add to your home, you will want to determine what your total electricity load is based upon what size of system that you will need, your changing energy demands throughout each day and during different seasons of the year, and what codes and regulations of your locality you will need to follow when installing a renewable energy system on your home or property. Local government officials or renewable energy companies in your area should be able to assist you with what is and is not permitted .
Based upon your personal electricity needs and the system that you choose, you must also decide whether you would prefer a renewable energy system that is a stand-alone system and disconnected from the grid, or one that is still connected to the grid and allows you to sell your excess power back to your utility provider.
Stand-alone (off-grid) renewable energy systems are particularly useful for people who live in remote locations and for those who prefer to be independent from power providers .
The recent invention of special batteries like the Tesla battery allows electricity storage from renewable energy systems for use during times when renewable sources of energy are less reliable, such as when wind dies down or when there is reduced or non-existent sunlight.
Modern battery technologies enable electricity generation from renewable sources to become a reliable source of power all of the time, and can be made to fit all types of buildings, including residential, commercial, and industrial.
But let’s have a look at the currently available renewable energy options for homeowners like you more in detail.
Renewable energy option for your home
#1 Electricity generation using solar energy
Solar photovoltaic systems allow for reliable electricity production at home. In particular, photovoltaic systems offer cost-effective and reliable power generation where connection to the traditional electrical grid is challenging.
Whether you are building a new home or purchasing a renewable energy system, the most common solution is solar power. Light from the sun is collected via solar panels. A solar panel creates the opportunity for particles of light to knock electrons free from atoms, creating the energy of electricity.
The average home in the United States uses about 900 kilowatt hours (kWh) per month. Generally, a square foot of solar panels can generate 10 or more watts. This of course is dependent upon the where you live and the direction the panels are situated in relation to the sun.
Solar panels can be placed anywhere they receive direct sunlight. It is common to place the panels on rooftops as they typically have an unobstructed path from the sun. They can also be installed in your yard. Another option if you are either building or replacing a roof is to use solar shingles instead of the panels .
Community shared solar power projects can also be an option in some communities where everyone in the community comes together to purchase a collective solar system to generate locally sourced solar power and receives a share of that power.
#2 Controlling the temperature of your house with solar energy
Solar power doesn’t just have to generate electricity for lights and miscellaneous use. The power of the sun can also heat your home. You are probably painfully aware that air conditioning and heating systems use more electricity than anything else in your home.
If you live in a hot climate and you have central air, you are aware of the spike in your electric bill during the hot months. Likewise, if you live in a cold climate, your electric bill in the winter months is higher for the extra power needed to keep your house warm.
While it might seem contradictory to cool your house with heat from the sun, that is exactly what solar air conditioning does. It uses water heated by the sun to power the air conditioning system.
As a bonus, the hot water produced for air conditioning or heating in the winter months, can also be used for other applications in your home when not in use. Depending on your setup, you can get the benefits of solar water heating with bonus air conditioning as well.
There are many different types of solar water heaters on the market, so do your homework to find the system that works best for you. Know too, that you may not have to invest in an entirely new HVAC system. Many existing heating and cooling systems can be modified to take advantage of solar energy.
#3 Solar water heating
Coming in second to heating and cooling costs is simply heating water. It is estimated that heating water accounts for 14 to 15 percent of the total energy consumed in the home . Consider installing a solar water heating system.
Solar water heaters (SWH) use the free energy from the sun to heat water to be used in a home or other building. There are plenty on the market, many advertising that they provide up to 70 percent of the energy needed for heating water directly from the sun.
How do solar water heaters work?
Solar water heaters work by converting sunlight into energy for heating water through the use of a solar thermal collector. The solar energy collector heats a fluid inside the heater that is then either pumped (“active” systems) or moved by natural convection (“passive” systems) into a hot water storage tank where the heat is then stored.
Storage tanks for solar water heaters are typically large in case there is bad weather and to ensure that enough hot water is available for use.
The hot water can be pumped through your radiators or simply through your existing water pipes and out your faucets or shower heads. It is much less expensive than using gas or electricity to heat your water, and it is easier to install than solar panels.
Types of solar water heaters
There are two general types of solar water heaters, passive SWHs and active SWHs. Both require an additional source such as an electric heating element or fuel oil central heating system that is activated when the tank falls below a particular low temperature threshold.
Combining solar water heaters with a backup heat source such as a wood stove chimney can allow these solar water heaters to be used year round while avoiding the use of fossil fuels or electricity to power them.
Passive SWHs are typically geared for warm weather climates. They require no electricity (will work even if there are blackouts) and can be installed yourself if you choose. To move the heat around, they rely on convection or heating the fluid in the system. They cost less than active systems and require little to no maintenance, but their efficiency is much less than an active system.
Active SWHs are available for both moderate and cold climates. These systems use electricity, but the cold climate active SWHs have special collectors that can be used in remote and off-grid situations with the right type of setup. They involve at least one pump that circulates the water or the heating fluid in the system. In addition to residential settings, such systems can also be used for commercial applications such as nursing homes, universities, and summer camps.
The type of solar water heating system that is required for a region essentially depends on how cold and hot it can typically get in that particular climate.
Advantages of solar water heaters
- Can provide large energy savings with relatively low investment, and will pay for itself within approximately three to five years.
- A much lower lifetime operating cost than conventional water heaters because the energy from the sun is free.
- When using only solar energy, these systems eliminate the use of fossil fuels to heat water, reducing a homeowner’s carbon footprint.
- Increase the value of a home.
- In passive SWH systems, you can have hot water even if the electricity goes out.
- Helps to protect from future energy bill rate increases.
- Rebates and other incentives may be available to help cover the cost of purchase and installation. Be sure to check with your local energy company and municipality to find out if any of these resources are available to you.
- Models are now available for just about any climate.
#4 Solar powered appliances help lower your monthly bills
If you are not ready to make the investment for full home solar power, take it step-by-step. There are a number of products available that run on their own solar systems that can markedly reduce your dependence on electricity.
One is a solar refrigerator. These were initially developed to answer the need for vaccine storage in remote areas and thus are very efficient coolers. They can use up to 80 percent less energy than conventional models, some models running on as little as 40 watts.
With an eye toward solar compatibility, these refrigerators have been built to be DC-powered, and they come in 12- and 24-volt configurations. Too, they are manufactured in a variety of sizes, from 5 to 19 cubic feet. They are available as refrigerator alone or can be purchased as a combination solar refrigerator-freezer .
Another household appliance that sucks up a lot of power and can run on solar energy is a solar oven. Solar ovens work by trapping sunlight to heat food. Solar ovens, easily built out of a few common materials, have been a popular science project for years. If this interests you, you can buy one. There are plenty on the market.
There are even solar cookers that work at night now, and in the early morning before the sun has had a chance to charge your cells and you need that cup of coffee. Think of the advantages. Not only do they heat your food for free, but they work during a power outage.
Do you need a water distiller system? Solar water distillers use the energy of the sun to distill saline or contaminated water into pure drinking water. Large units provide about 0.8 liters of pure water per sun-hour in temperate climates, which is about 1.5 gallons per day. Smaller solar water distillers deliver up to two quarts per day. You can build your own solar still or look to companies such as SolAqua or the Aquamate made by Echomax.
Do you need an attic fan? Direct-solar attic fans on the market are quiet and self-contained, moving between 850 and 1,250 cubic feet of air per minute, depending on sunlight and model size. Models on the market are activated by a thermal switch that kicks on when attic temperatures exceed 80 degrees Fahrenheit and even small ones can cool up to 1,200 square feet of attic space.
Could you use a water pump? Solar pumps are available for surface water and as submersible well units, manufactured in 12-volt, 24-volt and higher-voltage configurations.
New technologies are developing as this is being written. The point is that if you have a need for an appliance, do some research. It may be available as a stand-alone solar appliance.
The most notable weakness of solar power is that it only works when the sun is up. If you want to power your home when the sun is down, you’ll need to either invest in a second type of renewable energy or pay for electricity from the grid.
#5 Harnessing the power of the wind
More and more people are looking to wind power. If you live on a windy spot, this might be a better renewable investment than solar. Typically, for wind power systems to be effective, you need more than one acre of land with sufficient wind resources in the area.
It can be a more stable source and it can easily generate most, if not all of your electricity needs. Under the right conditions, such systems can reduce electricity costs by 90 percent. However, it is important to check local permitting and zoning requirements prior to installation because a wind turbine large enough to power a home often requires a permit.
If you are looking for a simpler solution or don’t have the extra land for a large wind turbine, check out a personal wind turbine like Southwest Windpower’s Air-X. It can produce up to 400 watts. This will offset some lighting and appliance usage. Another advantage is that it does not need the space a large windmill requires. It can be installed on top of a roof.
How to make a DIY wind turbine at home?
Home-made DIY wind turbines that can produce electricity using wind power are becoming increasingly popular because they are a much more affordable solution for many homeowners.
You should know that it is possible to build a wind turbine at home with simple materials available in hardware stores. This is because a wind turbine is essentially a mechanical device which is very similar to windmills.
There is certainly some homework that needs to be done before taking out your tools.
Step 1: One important thing you will need to do is to ensure that building a wind turbine makes sense in terms of the potential energy gains it will provide you.
If you are living in an area with infrequent or very low air currents, chances are building a wind turbine will not be particularly helpful. You need to measure the annual average wind speed for your area which will also help you determine whether your wind turbine would function in a cost-effective way.
Step 2: The second thing you need to do is ensure you are not breaking any local rules or regulations. Once you’ve established that, you would need to make sure you have the required space to set up your wind turbine. As a rule of thumb, 0.2 hectare is needed for a 3 kilowatts wind turbine and 0.4 is needed for one that generates up to 10 kilowatts .
Step 3: At this point, you can start thinking about your wind turbine and what kind of components you will need. What you choose to make yourself or buy off-the-shelf will largely depend on how confident you are with DIY but also if you have any experience in engineering.
One thing to keep in mind is that regardless of mild weather conditions, you should avoid buying cheap materials. The wind turbine will be exposed to a log of environmental factors and for health and safety reasons you need its constituent parts to be of solid make.
For instance, you can choose to buy or make your own wind turbine blades. These should be the correct size for your wind turbine to work efficiently. If you are making them yourself, it is recommended you choose to build them from wood or cross-sections of PVC pipes.
The optimal number of blades is three. An odd number reduces vibrations while adding blades adds weight to the turbine making it rotate more slowly.
Regarding the generator, the wind turbine will likely require one of high voltage and low rotations speed, generating at least 12 volts over a consistent period of time. While there are many online tutorials about making your own generator, it is safest to buy one if you do not have a background in electrical engineering.
Step 4: For the assembly including connecting all the electronic components, you will have to bear in mind that different tools and knowledge of certain techniques like welding is likely to be needed.
Before starting your project, please make sure you have read and understood the steps involved in putting together a wind turbine. Some of the most detailed tutorials can be found on wikihow.com and the personal website of an astronomer who built a DIY wind turbine himself.
#6 Hybrid solar and wind electric systems
By combining solar systems and wind systems together, you may be able to meet your electricity needs more efficiently than either type of system alone due to the differences in peak operating times of both technologies.
#7 Hydropower as a stable source of energy
Do you have a stream or river on your land? Micro-hydropower systems can generate electricity using streams, creeks, or other flowing water. If you have a source of flowing water, you can divert some or all of it to flow through a water turbine and power your home.
An engineer evaluating your source will definitely fine tune these instructions, but essentially your goal is to find the largest vertical distance the water will travel and divert that water so it flows through a turbine in a controlled manner. Depending on the amount of water and vertical distance, you may be able to produce a substantial amount of power. Residential hydropower systems can typically generate up to 100 kilowatts of electricity, with only 10 kilowatts of that capacity necessary to provide enough electricity to power a large home.
Unlike solar and wind, as long as the water flows, hydropower is stable and continuous, which means you’ll always get the same input no matter what. You’ll never have to worry that your generator won’t be able to power your home.
You will probably need to have a professional install a hydropower generator for you. That being said, if you have some engineering knowledge, you might be able to build one from scratch.
A simpler solution may be an in-stream generator if you have a fast-moving stream at least 15 inches deep. Like the name implies, drop-in-creek generators do not require much effort in the way of installation. And some products, like the 100-watt Ampair Energy UW100 will let you generate up to 2.4 kwh per day.
Hydropower can be harnessed for a single purpose as well. Do you get your water from a well or spring? Hydraulic ram pumps for moving water have been around for at least 200 years. Ram pumps use the flow and fall of water to push some of it uphill without electricity. The pumps work 24 hours a day, delivering from 14 gallons per day to well over 1,500 via larger models. Again, you can buy one or build your own.
If you have decided that you are ready to install any sort of renewable energy system in your home or on your property, there may be a number of incentives that can help to make such improvements more affordable including rebates, tax credits and special finance options.
Be sure to inquire with local energy provider, municipalities, and renewable energy companies to learn which incentives are available to you or check the official Database of State Incentives for Renewable & Efficiency.