Living Off Grid

Living off-grid is an aspiration for many people. You may want to ‘grow your own’ electricity and not be reliant on electricity companies. You may live in the middle of nowhere and be unable to get an outside electricity supply. Whatever your motive, there are many attractions for using solar power to create complete self-sufficiency.

Do not confuse living off-grid with a grid-tie installation and achieving a balance where energy exported to the grid minus energy imported from the grid equals a zero overall import of electricity. A genuinely off-grid system means you use the electricity you generate every time you switch on a light bulb or turn on the TV. If you do not have enough electricity, nothing happens.

Before you start, be under no illusions. This is going to be an expensive project and for most people it will involve making some significant compromises on power usage in order to make living off-grid a reality.

In this book, I have been using the example of a holiday home. The difference between a holiday home and a main home is significant. If you are planning to live off-grid all the time, you may not be so willing to give up some of the creature comforts that this entails. Compromises that you may be prepared to accept for a few days or weeks may not be so desirable for a home you are living in for fifty-two weeks a year.

Remember that a solar electric system is a long-term investment, but will require long-term compromises as well. You will not have limitless electricity available when you have a solar electric system, and this can mean limiting your choices later on. If you have children at home, consider their needs as well. They will increase as they become teenagers and they may not be so happy about making the same compromises that you are.

You need to be able to provide enough power to live through the winter as well as the summer. You will probably use more electricity during the winter than the summer: more lighting and more time spent inside the house mean higher power requirements.

Most off-grid installations involve a variety of power sources, such as a solar electric system, a wind turbine and possibly a hydro-generation system if you have a fast-flowing stream with a steep enough drop. Of these technologies, only hydro on a suitable stream has the ability to generate electricity 24 hours a day, seven days a week.

In addition to using solar, wind and hydro for electrical generation, a solar water system will help heat up water and a ground source heat pump may be used to help heat the home.

When installing these systems in a home, it is important to have a failover system in place. A failover is simply a power backup so that if the power generation is insufficient to cope with your needs, a backup system cuts in.

Diesel generators are often used for this purpose. Some of the more expensive solar controllers have the facility to work with a diesel generator, automatically starting up the generator in order to charge up your batteries if the battery bank runs too low on power. Advanced solar controllers with this facility can link this in with a timer to make sure the generator does not start running at night when the noise may be inappropriate.

A solar electric system in conjunction with grid electricity

Traditionally, it has rarely made economic sense to install a solar electric system for this purpose. This has changed over the past three years, with the availability of financial assistance in many parts of the world.

If you are considering installing a system purely on environmental grounds, make sure that what you are installing actually does make a difference to the environment. If you are planning to sell back electricity to the utility grids during the day, then unless peak demand for electricity in your area coincides with the times your solar system is generating electricity, you are actually unlikely to be making any real difference whatsoever.

A solar energy system in the southern states of America can make a difference to the environment, as peak demand for electricity tends to be when the sun is shining and everyone is running air conditioning units. A grid-tie solar energy system in the United Kingdom is unlikely to make a real difference to the environment unless you are using the electricity yourself or you live in an industrial area where there is high demand for electricity during the day.

If you are in the United Kingdom or Canada and are installing a solar energy system for the primary motive of reducing your carbon impact, a grid fallback system is the most environmentally friendly solution. In this scenario, you do not export energy back to the grid, but store it and use it yourself. When the batteries have run down, your power supply switches back to the grid. There is more information on this configuration later in this chapter.

There may be other factors that make solar energy useful. For example, ensuring an electrical supply in an area with frequent power cuts, using the solar system in conjunction with an electric car, or for environmental reasons where the environmental benefits of the system have been properly assessed.

One of the benefits of building a system to work in conjunction with a conventional power supply is that you can take it step by step, implementing a smaller system and growing it as and when finances allow.

As outlined in chapter three, there are three ways to build a solar electric system in conjunction with the grid: a grid-tie system, a grid interactive system and grid fallback.

You can choose to link your solar array into the grid as a grid-tied system if you wish, so that you supply electricity to the grid when your solar array is generating the majority of its electricity and you use the grid as your battery. It is worth noting that if there is a power cut in your area, your solar electric system will be switched off as a safety precaution, which means you will not be able to use the power from your solar electric system to run your home, should there be a power cut.

Alternatively, you can design a stand-alone solar electric system to run some of your circuits in your house, either at grid-level AC voltage or on a DC low-voltage system. Lighting is a popular circuit to choose, as it is a relatively low demand circuit to start with.

Grid Fallback and Grid Failover systems

As a third alternative, you can wire your solar electric system to run some or all of the circuits in your house, but use an AC relay to switch between your solar electric system when power is available, and electricity from the grid when your battery levels drop too low. In other words, you are using the grid as a power backup, should your solar electric system not provide enough power. This setup is known as a grid fallback system.

Grid fallback and grid failover are both often overlooked as a configuration for solar power. Both these systems provide AC power to a building alongside the normal electricity supply and provide the benefit of continued power availability in the case of a power cut.

For smaller systems, a solar electric emergency power system can be cost-competitive with installing an emergency power generator and uninterruptable power supplies. A solar electric emergency power system also has the benefit of providing power all of the time, thereby reducing ongoing electricity bills as well as providing power backup.

The difference between a grid fallback system and a grid failover system is in the configuration of the system. A grid fallback system provides solar power for as much of the time as possible, only switching back to the grid when the batteries are flat. A grid failover system cuts in when there is a power cut.

Most backup power systems provide limited power to help tide premises over a short-term power cut of 24 hours or less. Typically, a backup power system would provide lighting, enough electricity to run a heating system and enough electricity for a few essential devices.

As with all other solar projects, you must start with a project scope. An example scope for a backup power project in a small business could be to provide electricity for lighting and for four PCs and to run the gas central heating for a maximum of one day in the event of a power failure.

If your premises have a number of appliances that have a high-energy use, such as open fridges and freezer units, for example, it is probably not cost-effective to use solar power for a backup power source.

Installing any backup power system will require a certain amount of rewiring. Typically, you will install a secondary distribution panel (also known as a consumer unit) containing the essential circuits, and connect this after your main distribution panel. You then install an AC relay or an Automatic Transfer Switch between your main distribution panel and the secondary distribution panel, allowing you to switch between your main power source and your backup source:

In this above diagram, a second consumer box has been wired into the electrical system, with power feeds from both the main consumer box and an inverter connected to a solar system.

Switching between the two power feeds is an automatic transfer box. If you are configuring this system to be a grid fallback system, this transfer box is configured to take power from the solar system when it is available, but then switches back to grid-sourced electricity if the batteries on the solar system have run down.

This provides a backup for critical power when the normal electricity supply is not available, but also uses the power from the solar system to run your devices when this is available.

If you are configuring this system to be a grid failover system, the transfer box is configured to take power from the normal electricity supply when it is available, but then switches to power from the solar system if it is not.

One issue with this system is that when the transfer box switches between one power source and the other, there may be a very short loss of power of around 1/20 of a second. This will cause lights to flicker momentarily, and in some cases may reset electronic equipment such as computers, TVs and DVD players.

Many modern transfer boxes transfer power so quickly that this is not a problem. However, if you do experience this problem it can be resolved by installing a small uninterruptable power supply (UPS) on any equipment affected in this way.

You can buy fully built-up automatic transfer boxes, or you can build your own relatively easily and cheaply using a high-voltage AC Double-Pole/ Double-Throw (DPDT) Power Relay, wired so that when the inverter is providing power, the relay takes power from the solar system, and when the inverter switches off, the relay switches the power supply back to the normal electricity supply.


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Making and Saving Money with Solar

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Creating energy with solar is not only environmentally friendly, it can also be good for your bank account too. Whether you are considering solar as a way of offsetting your electricity bill in your home or business, or if you are considering a solar installation to avoid the high cost of connection to the electricity grid, solar can often save you money.

In addition, there are often subsidies, grants or other financial incentives available to make solar a more attractive purchase. In some cases, these incentives alone are sufficient to pay for your solar installation over a period of a few years.

Installing electricity to a new building

If you are looking to install an electricity connection to a new building, installing your own solar power station can often be cheaper than installing the power lines. This is particularly true if you live in a rural location where power lines may not run close to the building. Even simple connections to a roadside property can easily cost several thousand, and if your property is suitable for solar power, it can quite easily become more cost effective to go completely ‘off grid’ and create all of your own power from solar.

Of course, there are limitations to this approach. You have to produce all the energy that you use, and you will need a watchful eye on your electricity usage to make sure you do not run out. Yet this can be a practical option for many locations where a conventional electricity connection is otherwise unaffordable.

Subsidies, grants and other financial incentives

Solar has traditionally been a more expensive source of electricity production when compared with traditional power sources. Prices have fallen significantly over the past few years but it is still the case that for many installations, solar does cost more than other power options.

Various countries offer financial incentives for people to invest in solar, either through grant schemes that help pay some of the cost for installing solar, or more commonly, through a feed in tariff, renewable energy certificates, export tariffs, net metering or a combination of all four.

As solar prices continue to fall, these subsidies are being reduced. Some countries have already reduced their schemes to nominal levels and it is widely expected that virtually all subsidies will be withdrawn by the end of the decade. However, the recent COP21 World Climate Summit held in Paris during December 2015 brought environmentally friendly power generation sharply back into focus. Many governments are now reviewing their incentives for encouraging the uptake of solar and this is likely to prolong or extend some of the schemes for longer than previously anticipated.

Grant Schemes, Low Interest Loans and Tax Rebates

Grant schemes, low interest loans and tax rebates are paid for directly out of government funds. Consequently, they can be unpopular with some politicians and the wider electorate, who often resent tax-payers money being used as a green energy subsidy.

Grants for installing solar are now becoming much rarer, although a few schemes are still available around the world for specific applications. In the United Kingdom, for example, there is a Rural Development Programme that has a fund to help farmers, land owners and community co-operatives. This fund consists of a grant of up to £20,000 to test the viability of a renewable energy system, followed by a low-interest, unsecured loan to fund up to 50% of the installation costs for a wind, solar or hydro-power project.

In several States of the United States, including California, there are tax rebates for solar energy, whether these are installed for residential, commercial or agricultural purposes. There are also rebates for solar installations for low-income families and for multi-family affordable housing projects. The exact detail of these schemes does vary between counties and states.

These are just two examples of the schemes that are available. There are other examples and if you are considering installing a solar energy system, it is worth investigating whether there are any grant schemes or tax rebates that may help you fund part of the cost.

Feed In Tariffs

A feed in tariff encourages home owners, business owners, communities and private investors to generate their own renewable energy and receive financial compensation for this energy. The feed in tariff has been one of the principle reasons why residential solar has become so immensely popular in many parts of the United States and Europe over the past six years.

Feed in tariffs typically work by providing a payment for every kilowatt-hour of electricity generated by a solar energy system. The payment is made whether the electricity is used by the owner of the system, or if it is exported. The tariff is typically guaranteed for around twenty years and most schemes incorporate index-linked price increases to ensure the value of the income from the tariff matches inflation.

Feed in tariffs are usually administered and paid for by the energy companies rather than by government. In the United Kingdom, for example, all consumers pay a green energy levy on their energy bills. This levy is then used to pay for various green initiatives, including paying the feed in tariff. Solar owners are paid the feed in tariff every three months, either receiving it as a discount from their energy bills or by having the money paid directly into a bank account.

Some feed in tariff schemes only relate to grid-tied systems, whereas other schemes offer feed in tariffs for both grid-tie and stand-alone systems.’

Adapted from the new edition of the world bestselling Solar Electricity Handbook. The rest of this article can be found exclusively at Blue and Green Tomorrow….

Solar Electricity and the Environment

Emissions and the environmental impact of power generation is back in the spotlight, thanks to the COP21 World Climate Summit held in Paris during December 2015. In order to achieve the targets set by the agreement, there has to be a big shift away from traditional power generation towards greener energy production.

No power generation technology is entirely environmentally friendly. Hydro-electric power stations have an impact on water courses and impacts local wildlife. Wind turbines account for a number of bird deaths every year. Building hydro, wind or solar equipment also has a carbon footprint that has to be taken into account. Yet this carbon impact is a tiny fraction of the carbon footprint associated with more traditional power generation technologies.

Once installed, a solar electric system is a low-carbon electricity generator. The sunlight is free and the system maintenance is extremely low. There is a carbon footprint associated with the manufacture of solar panels, and in the past this footprint has been quite high, mainly due to the relatively small volumes of panels being manufactured and the chemicals required for the ‘doping’ of the silicon in the panels.

Thanks to improved manufacturing techniques and higher volumes, the carbon footprint of solar panels is now much lower. You can typically offset the carbon footprint of building the solar panels by the energy generated within 2–3 years, and some of the very latest amorphous thin-film solar panels can recoup their carbon footprint in as little as six months.

Therefore, a solar electric system that runs as a complete stand-alone system can reduce your carbon footprint, compared to taking the same power from the grid.

In general, the same is now true of grid-tie solar. In the past, the power companies have struggled to integrate renewable energy into the mix of power generation sources. This has meant that whilst the energy produced by solar panels was non-polluting, it did not necessarily mean that there was an equivalent drop in carbon production at a coal or gas-fired power station.

However, over the past few years, power companies have become far better at predicting weather conditions in advance and tuning the general mix of power generators to take advantage of renewable energy sources. This has ensured a genuine carbon reduction in our energy mix.

Of course, the sunnier the climate, the bigger benefit a solar energy system has in reducing the carbon footprint. In a hot, sunny region, peak energy consumption tends to occur on sunny days as people try to keep cool with air conditioning. In this scenario, peak electricity demand occurs at the same time as peak energy production from a solar array, and a grid-tie solar system can be a perfect fit.

If you live in a cooler climate with less sunshine, peak energy demand often occurs in the evening, when solar energy production is dropping. This does not negate the carbon benefit from installing solar, but if you want to maximize the carbon benefit of a solar energy system, you should try to achieve the following:

  • Use the power you generate for yourself
  • Use solar energy for high load applications such as clothes washing
  • Reduce your own power consumption from the grid during times of peak demand
  • Store some of the excess solar energy production using batteries and use it in the evening

Environmental efficiency: comparing supply and demand

There is an online calculator to map your electricity usage over a period of a year and compare it with the amount of sunlight available. Designed specifically for grid-tie, this calculator shows how close a fit solar energy is in terms of supply and demand.

Whilst this online calculator is no substitute for a detailed electrical usage survey and research into the exact source of the electricity supplied to you at your location, it will give you a good indication of the likely environmental performance of a solar energy system.

To use this online calculator, collate information about your electricity usage for each month of the year. You will usually find this information on your electricity bill or by accessing your electricity account online. Then visit, follow the links to the Grid-Tie Solar Calculator in the Online Calculators section.


Greedy for Power


We have a problem in the developed world. We’re greedy for more and more power. We can never have enough. We take energy for granted. Plug a hair dryer or a kettle into a socket and switch it on and it just works. Cold? Turn up the thermostat or adjust the timer on the central heating and we’re warm in minutes. We don’t have to think about the amount of energy we want to use, it is there for us whenever we want it at the flick of a switch.

It’s the same with our cars. Get in, fire up the engine and you have an enormous amount of power under your right foot. Even a small family car has an engine that could produce enough power to provide electricity for one hundred houses or more.

What has made all this possible is fossil fuel: oil, gas and coal. These fuels are amazing. They pack a huge amount of energy in a very compact form. The amount of energy in one litre of petrol (gasoline) is around the same as the energy stored in 250kg (550 pounds) of batteries. We’ve become pretty good at transporting fossil fuels around the world and we use them when we need them. As a form of usable energy, fossil fuels are pretty much unbeatable.

Of course, there are problems with fossil fuels. Supply and demand, climate change, the occasional war… I’m not going to list them all here. But the issue is this: we have become addicted to oil and the benefits it gives us. We don’t want to lose those benefits. Whatever we use to replace fossil fuels, the public demands that we should be able to carry on doing the same things we currently do.

And that is a big mountain to climb. Renewable energies are very good at producing smaller amounts of energy, but harnessing it on a utility scale is a huge undertaking. A single solar photovoltaic panel will produce, at most, around 300 watts of power: enough to watch TV, perhaps, but only a fifth of the power required to run a washing machine. Wind turbines can produce far more, but in comparison to the power output of a conventional power station, the numbers are tiny.

One of the biggest issues with most sources of renewable power is that we get the power when nature dictates. Solar power relies on sunlight, wind turbines rely on wind. Even hydro-power, which is one of the more reliable and controllable sources of renewable energy, ebbs and flows with the seasons.

That simply does not fit in with our demands for energy when we want it. It means that renewable energy technologies have to be supplemented with other forms of energy production. Here in the UK, a huge wind turbine building scheme now means that it is quite common for wind power to supply 20% or more of our nation’s electricity at any time.  Yet on a calm day, the power output from wind turbines can be as low as 1% of our demand. The supply of this energy can fluctuate in just a few hours, making it difficult to manage supply against demand.

Traditional power stations struggle to manage this fluctuation. Coal and nuclear power stations are at their most efficient when running at a constant rate. In the UK, gas-turbine power stations are being used as load-balancers, increasing production when wind energy is low and reducing it when wind energy is higher.

Technology is evolving and we are resolving the issues. Tidal and wave energy, for example, has the potential to provide large quantities of reliable around-the-clock energy, whilst the development of stored solar thermal technologies in Spain demonstrates a way of providing a reliable 24-hour energy source from the sun. Right now in Sweden, I’m working on a wind farm project working with hydro-electricity to handle the peaks and troughs. It has the potential to eradicate the need for fossil fuels for electricity production in Sweden within the next four years.

We are getting closer. We have the technology and the ability to generate an abundance of electricity from renewable sources. We will be able to do it cost effectively and we will be able to have energy when we want it, not when nature decides to give it to us. We don’t have all of the answers yet, but we will do.

Will fossil fuels be redundant within my lifetime? Probably not. But at least we will have broken our addiction to oil and have a greener and cleaner source of energy, provided by nature, which will never run out.


Written by Michael Boxwell, bestselling author of the Solar Electricity Handbook.

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