US Number One for Solar

We’ve been discussing the US solar industry in the last few weeks here on the Greenstream blog, wondering about the impact of climate change denier Trump’s election. Recent statistics, due to be published 9th March by GTM Research and the Solar Energy Industries’ Association indicate that the current solar industry in the US is at an all time high and only set to increase, Presidential denial notwithstanding.

The US solar market had its biggest year to date in 2016, doubling its annual record at total installations of 14,626 megawatts. 22 states each added more than 100 megawatts. Minnesota and Massachusetts led the community solar record, while most of the growth was due to an increase in utility-scale solar as it becomes ever more cost competitive with fossil fuels. Solar accounted for 39% of all new additions across all fuel types.

This makes the US, for the first time ever, the number one source of solar generation. Small surprise then that our bestselling Solar Electricity Handbook consistently tops the US solar chart!

 

 

 

 

Renewables are Radical Again

Renewable energy has been the sensible and increasingly cost-effective choice for homeowners and corporations for quite some time, a far cry from the days of renewable energy projects in the developed world being the preserve of end-of-world conspiracy theorists and hippies. Yet since the inauguration of President Trump – who stated in 2015 that renewable energy was ‘just an expensive way of making the tree-huggers feel good about themselves’ – renewables may become a counter-culture choice once again, as Trump makes climate change denial the official stance and attempts to suppress the voices of those who claim otherwise. Renewables are radical once more.

Except, the voices that cry for energy revolution are no longer voices in the wilderness. Solar and wind have become mainstream, and clean energy is no longer a niche project. Most industry insiders have expressed a belief that it is too late for Trump to stem the tide of energy reform, no matter how vehement his denial or how fossil-fuel friendly his policies

Let’s hope they’re right. Meanwhile, Trump moves forward on tossing out Obama’s Clean Power Plan and cutting longstanding tax subsidies….

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How Trumps Election Could Affect Renewables

Well, for a start, Trump has dismissed climate change in the past. He seems to believe it doesn’t exist, and in fact is a myth created by the Chinese.

He also pledged to ‘stop the war’ on the coal and mining industry and stated that shale energy was the way forward and would ‘unleash massive wealth’ for America, ignoring the fact that both industries are in competition with each other, making it rather difficult to support them both. Solar and wind, the renewable energy sources we strongly advocate here at Greenstream, were dismissed as too expensive in spite of the fact that in recent years with lowered costs and innovations in technology, that argument is no longer as viable.

My guess is that most renewable energy enthusiasts, if voting purely on the issues of energy and climate change, would have gone for Clinton, whop promised to continue the strides forward taken during Obama’s residency. Trumps election then has surely come as a blow.

So in real terms, what could this mean? Back in 2009, Trump seemed to be a supporter of renewables; he gave his signature along with others to a letter to Obama before the Copenhagan Climate Summit, calling for an increase in clean energy technologies. But in his recent campaign pledges he has gone against that in dramatic fashion, promising to rescind Obamas Clean Energy Plan, back out of the Paris climate agreement and has been vocal about his dislike of the wind farms in view of his golf course.

It’s not looking good.

But I think it’s important not to catastrophise. Donald Trump  cannot, in four years, President or not, single-handedly dismantle the renewable energy revolution. He cannot stop individual states from pursuing reduced emissions. He cannot prevent the slide of the coal industry, for all his ‘war’ rhetoric. He can’t abolish the EPA without the support of Congress. His plans to spend a trillion dollars building new roads isn’t likely to be supported by conservative Republicans. He cannot change the fact that clean energy technology continues to get better and better and cheaper and cheaper.

Four years.

We can wait, Mr Trump.

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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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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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