Solar Power for Houses: Your Residential Solar Power System

People turn to solar power for several different reasons:

• High energy prices
• Climate change
• Fossil fuel depletion
• Solar energy costs are coming down

When these factors are taken into account, it’s no wonder that people are going solar. Here are some more data on each:

High Energy Prices

While we’ve been hearing most about high oil prices over the past few years, electricity prices have also been going up in many places. When combined with the price of solar photovoltaics coming down, solar looks a lot more practical than it used to. The recession may have lowered energy prices temporarily, but how long will that last? The volatility in energy prices also makes solar power attractive because you don’t get left vulnerable to energy price spikes when you produce more electricity than you use.

Climate Change

Operating a residential solar power system does not produce CO2. While some CO2 is produced during the making of solar panels and other elements of the system, there are vastly lower emissions than from the production of electricity from oil, gas, or most especially coal. Thus, every solar photovoltaic array very slightly reduces the likelihood of catastrophic climate change.

Fossil Fuel Depletion

The easiest, cheapest oil gets used first. Most oilfields and wells being brought into use now produce oil that is difficult to access or process in some way. This tends to keep oil prices high. It looks increasingly likely that we have hit Peak Oil, which means diminishing supplies of oil in the future no matter how much oil exploration and development we do.

While most electricity does not come from oil, prices for all forms of energy are linked and are likely to become increasingly so as more electric vehicles are made, and even more so if Coal-to-Liquids technology is used on any large scale. In the US, coal is the largest source of electricity. If Coal-to-Liquids plants are built to compensate for Peak Oil, this would increase the price of coal, and therefore that of electricity.

Coal supplies are not endless and it looks increasingly likely that there may be less recoverable coal than commonly thought. This is likely to raise electricity prices in the future. In such an environment renewable energy sources, including solar, look better and better.

Residential Solar Energy is Becoming More Affordable

The current recession has resulted in people buying less. During the high oil prices, producers of solar panels and other components vastly increased capacity. When the recession hit, they found themselves with excess solar photovoltaic systems, components, and raw materials. Prices dropped.

The USA is about to start giving larger rebates for solar which will help increase affordability for a very large, affluent market. This is likely to increase demand for solar energy, which might prevent lowering of prices in the short term, but will likely reduce them in the long term by increasing the capacity of industry. China has also started manufacturing solar panels, which is likely to reduce solar panel price due to economies of scale and cheaper labor in that country.

In California there is at least one company that offers leases of solar photovoltaic systems with guaranteed electricity prices lower than that of some utilities in that area. This increases affordability of solar by eliminating the high start-up costs of home solar systems which act as the largest barrier to going solar for many people.

More Information:

Fossil Fuel Depletion, Peak Oil and Energy Prices:

The Oil Drum

Richard Heinberg’s Museletter

Heinberg, R. 2009 Blackout: coal, climate and the last energy crisis. New Society Publishers.

Trends in Renewables and Renewable Energy News:

Renewable Energy World

The less power you use, the less expensive the home solar system you will need to power your home.   Increasing energy efficiency is a great way to do this.   Recent appliances are more energy-efficient than older ones but the extent of the energy savings varies greatly between different types of appliances.  The two most energy-intensive appliances in most homes are refrigerators and dryers.

Why You Need an Energy Efficient Refrigerator

Refrigerators use a lot of energy.  New refrigerators use a lot less energy than older refrigerators.  There is also a great difference in energy use between different refrigerators.  The standard advice is to buy a new energy efficient refrigerator if your current fridge is more than 10 years old, as the energy savings will pay for the the new refrigerator.

New Energy Star refrigerators use 50% less electricity than the average ten year old refrigerator.   If you live in BC, BC Hydro runs a fridge buy-back program in an effort to reduce electricity use. EnergyStar is a program that certifies energy efficient appliances.   If you live in BC Canada, BC hydro has rebates for buying EnergyStar appliances.   Many other areas probably have similar programs.

Well-maintained appliances are more efficient than poorly maintained ones, as well as doing their jobs better.   If you cannot afford to replace an aging appliance, performing regular maintenance will help minimize its its electricity use.  This will not reduce electricity use to the level of a new appliance, but it will reduce it greatly over a poorly maintained one.

Energy Efficient Dryer or Clothesline?

Dryers use a lot of energy, sometimes as much as the refrigerator despite the fact that they aren’t on all the time. Ideally, one would hang clothes to dry outside, thus using no electricity at all, but in many places this is inconvenient in the winter. Clothes will dry in the cold, but not if it is raining on them.

Drying outside is against bylaws and home owner association regulations in some places. Do be aware that many of these regulations are being challenged and declared illegal, so if you want to dry outside you may be able to do so even if you weren’t a year ago. The movement to make anti-drying regulations illegal is often referred to as the ‘right to dry’ movement, and it is widespread.

Indoor drying racks also work, but do take space while the clothes are drying.  The most inventive indoor drying rack I’ve seen was hung from the ceiling of a kitchen and hauled up and down with a rope and pulley system.  This made extremely efficient use of space and allowed a washer’s worth of clothes to be dried indoors in Britain in the winter.  It worked well enough that the house did not have a dryer.  If you have a small household that does not produce huge amount of laundry this system could well work for you.  It is it is hard to get more electricity efficient than this!

If you do want a dryer, an energy-efficient dryer will save on electricity, although not as much as letting half of each load air-dry.

Energy Efficient Clothes Washers

Front loading washers are more efficient than top loading washers.  If you don’t have large amounts of laundry, a compact washer will save you electricity.  If you do have large amounts of laundry, a full size front loader may be your best bet, as doing one larger wash takes less energy than doing multiple smaller washes.  Some dryers are more efficient than others, so pick an efficient one.

Energy-Efficient Dishwasher or Handwashing?

An energy-efficient dishwasher that is fully loaded uses less hot water than hand washing.  However, this requires that you load it fully.  If you only ever wash small loads at once, hand washing may be more efficient.

There are also energy efficiency improvements to be found with cooking appliances, but they really deserve an article of their own.

Increasing energy conservation and energy efficiency are the most cost effective ways to reduce the amount of money you pay for energy.  Before you invest in alternative energy sources, you should check that your house uses as little energy as possible while still allowing you the lifestyle you want.   Of the two approaches, the simpler is energy conservation.

Energy conservation involves using less energy by doing things like turning off the lights when we’re not in the room.  There is no upfront cost to such actions, although they do typically require behavior changes.

Ways to reduce your power use through energy conservation

• Turn all lights out when you leave the room
• Set your computer to fall into hibernation mode when it is not in use
• Unplug appliances when not in use, or get a power bar and turn the power bar off at night
• Buy a timer for your home’s thermostat so that your home will be warm when you’re home and moving about and cooler at night and when you’re at work
• Turn your home’s thermostat down a couple of degrees Celsius and wear a sweater – presuming your home is not leaky enough that you’re wearing a sweater anyway and freezing cold besides
• Turn the TV off if you’re not watching it

Basically, if you aren’t using it, it shouldn’t be on.

Energy efficiency involves using appliances that can do the same amount of work with less energy.  It does not involve you changing your daily behaviour.  The classic example is replacing incandescent lighting with compact fluorescent, but it goes far beyond this.  The largest use of electricity in many homes is heating.  By insulating the house, the amount of energy required to heat the house is reduced.

Cheap ways to reduce your power use through energy efficiency

• Replace incandescent bulbs with compact fluorescents
• Insulate your hot water heater
• Insulate your hot water pipes
• put plastic film over windows during winter

More expensive, but very useful

• Buy an energy-efficient refrigerator if your current fridge is more than 10 years old
• Insulate your ceilings, walls and floors
• Replace single-glazed windows with double or triple glazed windows

Of course, if you really want to increase energy efficiency there are a variety of methods for passive solar heating, but that is beyond the scope of this article.

When you install that new appliance…

I once lived in an apartment where the landlord had replaced all the windows with new windows that were supposed to be much better insulated and lose less heat.   However, he had installed them badly and there were gaps between the windows and the frame.  One of the gaps was so large you could see right through it to the outside.   Because of this, the house would not stay warm despite the new windows and the landlord complained about his energy bills to us.  Meanwhile, we complained that we were always cold.

This shows the importance of installing new energy efficient objects correctly.  If installed incorrectly, the object may well work badly if it works at all, and you may have done a lot of work and spent a lot of money for no energy savings.  So do it right the first time!

Pros

The most obvious advantage to solar energy is no operational carbon emissions.  Other advantages include reduced dependence or even complete independence from fluctuating energy markets and efficient power generation in areas that do not have access to a power grid.  In areas that do not have access to the power grid, it is frequently cheaper to buy a photovoltaic system than it is to pay to extend the grid, or to buy and run a diesel generator.

While energy prices have gone down recently with the global recession, it is unlikely that they will stay down.  When the economy improves oil prices will likely go back up, and energy prices in general will probably follow.  Once your solar panels are set up, the vast majority of your costs have already been paid, and rising electricity prices will be something that happens to other people.

In certain areas of the USA, there are programs that will let you lease solar Grid-tied Systems. This eliminates the high start-up cost problem if you are lucky enough to live in one of those areas.

Cons

There are also disadvantages to solar photovoltaic power.  Solar energy requires sunlight.  Photovoltaics do not produce power at night, and the amount of power they produce on cloudy days is much reduced from what they produce in sunlight.  They also produce more electricity during the summer than in the winter.  This is an advantage if your air-conditioning bills are higher than your heating bills, but in colder climates this is a disadvantage to solar power.  In climates with many cloudy days, power output is reduced from its full potential, which means that your initial investment takes longer to pay back than you might expect from tests in Spain or California. 

Purchasing and installing a solar system involves a substantial outlay of capital.  Prices for solar photovoltaic sytems are falling, but the cost is still prohibitive for many people.

Sources:

Home Power Magazine http://www.homepower.com/home/

Solar Photovoltaic Cost and Price Trends Retrieved May 16, 2009 http://www.solarbuzz.com/StatsCosts.htm

The exact pros and cons of photovoltaic solar power depend partly on whether you have a grid-tied system or an off-grid system.  So, what exactly are those pros and cons?

Off-grid Solar

Off-grid solar systems require substantial maintenance because of the battery banks necessary for storing electricity.  These batteries require occasional replacement and can be a fairly expensive investment on top of the solar panels.  However, if you live far from the power grid it can be far cheaper to have a solar system than to pay for connection to the grid.  Also, if the grid goes down your power source will not be affected.

Grid-tied Solar

Grid-tied systems without battery backup are the cheapest to set up for most people.  They do not offer any protection if the power grid they are tied into goes down, but they do offer the possibility of selling excess power to the local power company provided that the power company is set up to accept that.  This should be checked before you set up a Grid-tied solar Power System.

Grid-tied Solar with Battery Backup

It is also possible to set up a system that is Grid-tied but has a backup battery bank.  This is considerably more expensive than the standard batteryless Grid-tied System, but it means that if the grid goes down you will not have a power outage due to that failure.

In the end, which system is best depends on your needs and how you plan to use your photovoltaic array.  Photovoltaic power is not a one size fits all technology, and while the array of options in systems can be confusing, at least it gives you a good chance of obtaining a system that suits your needs.  More information on solar power and photovoltaic systems can be found at http://www.homepower.com/basics/solar/, as well as many other places on the web.