Everything you Ever Wanted to Know About Solar Panels for Domestic Power, but Were Afraid to ask

Chapter 1 - Wholesale energy use & price

EVERYONE & EVERYTHING in the developed world needs & uses electrical energy. Every home has electrical appliances that use electricity; therefore every household faces a sizeable annual bill for their energy use.

No doubt, most households have washing machines, fridge freezers, televisions, radios, computers, phones, DVD players, satellite receivers, hi-fi’s, microwave ovens, alarm clocks, lighting, heating. The list goes on & on. Yet, using each & every one of these appliances costs money to run & this cost is set to rise year on year as fossil fuels are slowly depleted & demand for electricity rises.

Whilst demand for fossil fuels increases, so too will the cost. It is a simple case of demand outstripping supply which causes this monetary increase in costs.

In the UK, the ‘National Grid’ predicts the cost of electricity to double by 2035 & gas to rise by 33% over the same time period. This is due to various factors, depletion of fossil fuels, governmental ‘green energy incentives’, lack of investment & most telling, the fact that by 2035, the UK is predicted to need to import 90% of its energy needs[1]. In addition, the US Energy Information Administration (EIA) also predicts an increase of 48% in total world energy demand by 2040[2].

The cost of obtaining energy has also risen 20% since 2009 & will clearly continue to increase; it therefore makes fiscal sense for all households to source as much energy as possible from cheaper alternatives. In addition to rising prices, the likelihood of future power cuts also increases dramatically. The UK’s Big Infrastructure Group (BIG) has warned that in the UK, the spare capacity of electrical energy that was ready to be delivered to consumers has fallen sharply in recent years. In 2011 - 2012 it was 17%, whilst in 2016 - 2017 it had fallen to 1%, therefore increasing the likelihood of blackouts[3]. BIG are not alone in predicting blackouts in the UK, the Institute of Mechanical Engineers predict that the UK will only have half the energy it needs by 2025 & they have also stated that The UK is facing an electricity supply crisis[4].

Since these predictions were made, both the UK & the EEC have announced that they intend to legislate to outlaw the sale of all new diesel & petrol vehicles by 2040[5]. The Green Alliance has stated that the UK grid is not ready for the anticipated demand that electric vehicles will place on the grid & that blackouts will occur as a result because it takes the same amount of electricity that an average household uses in three days to charge one electric car overnight[6]. They add that by 2025, 700,000 UK consumers will be experiencing blackouts due to this level of demand & also because of damage caused by increased levels of strain on the UK network. The UK electricity network was never designed to cope with these rising levels of predicted loads.

Luckily, the green energy brigade has been busy developing viable solutions for the energy market. Photovoltaic cells have halved in cost since 2008 & seen an overall 100% reduction in price since 1977[7]. In that time battery technology has also increased whilst the costs have decreased. The cost of batteries are predicted to continue to reduce in cost whilst the costs of fossil fuels increase[8]. It is predicted that there should be a further 70% decrease in battery costs by 2050. There are many energy companies currently researching battery technology which is being funded by car manufacturers, mobile phone companies & many others. Therefore it can be clearly seen that whilst there will be an incremental cost increase on domestic electricity, the cost of renewable energy solutions are set to plummet.  The sun & wind are currently free resources. They will remain to be a free resource until the government decides to levy a tax on them. Until that time, these free energy sources should be exploited to the fullest.

Therefore, the next logical step would be to look at the individual components that make up the installations that have the potential to save every household real money & thereby act as an investment, saving money for many years.

Chapter 2 - The components used in every system

ALL INSTALLATIONS FOLLOW the same basic design principles as they are all made from the same basic components & operate in the same way. The only difference between any given system is the size & complexity of the individual elements. For instance, one system may have 20 batteries, another 200. One may have 4 photovoltaic panels, another may have 40. One may store energy on site to be used by the homeowner; another may opt to sell the electricity directly to the ‘National Grid’. There is no single correct solution to any given installation, but there are always better options to consider when undertaking the design. Cost for most will be a major factor when selecting individual components as these systems are an expensive investment. However, as previously stated, the costs are predicted to reduce significantly over the coming years.

The concept in a nutshell

EVERY SYSTEM COLLECTS energy, transforms it into a useable form & then makes it available for the user. None of these systems create electricity; they just transform one form of energy into another (solar energy & kinetic energy into electricity). This is all due to one fundamental law of nature: energy cannot be destroyed, but it can move from one form to another. This is a system that everyone is familiar with. For instance, as a tree grows it collects solar energy & converts it into sugar to fuel its life systems. It also stores some of that energy within its trunk, branches & leaves. It has transformed solar energy into a form of energy that is more useful for it to use. We also can convert it into a form of energy that is more useful to us by simply burning the tree, thereby transforming the energy that the tree has stored into heat energy & a little back into light energy.

Another example could be: plants harness solar energy & convert it into sugar to fuel its life systems. It also stores some of that energy within its self, animals (including humans) eat the plants & use what the plants have made, to fuel themselves. It’s not magic; it is just harnessing what nature does for our own benefit. Nature has been doing it for millions of years as it is so efficient. Harnessing solar & kinetic energy (solar & wind power) is just another method that we can harness for our needs.

The system components

AS STATED PREVIOUSLY, all systems consist of the same basic components. They are as follows:

Collection elements:

PHOTOVOLTAIC (PV) CELLS – these collect solar energy & convert it to useable electricity.

Wind turbines – these collect wind (kinetic) energy & convert it to useable electricity. The easiest way of understanding it, is by imagining a battery powered hand fan. Instead of the battery powering a motor that spins the blades to move the air, these wind turbines blades are turned by the wind & that energy is converted into electricity. It is the same principle of the hand fan, but bigger & working in reverse.

Water turbines (aka water wheel) – these collect water (kinetic) energy & convert it to useable electricity. They work in exactly the same way as a wind turbine, but use moving water rather than moving wind. Water turbines are beyond the scope of this book as very few people have a suitable water source in their back gardens.

Control elements:

CHARGE CONTROLLER – this acts as a buffer between the collection elements & the batteries. It is a clever piece of electronics that regulates the supply so that the batteries are protected from any electrical charge that could damage the batteries.

Inverter – this inverts the batteries DC output into AC output.  Here in the UK & Europe, the nation’s supply is 230v AC; in the USA they have 110v DC. It is therefore important to know what form of electricity your household appliances need to run & also whether it is an AC or DC supply that they require.

Store/Supply element:

THE BATTERIES – THESE store the electricity that has been harnessed by the system & stores it until the power is needed by the consumer. Here is a simplistic view of how these components all fit together:

FIGURE 1 SIMPLISTIC view of the components (P Xavier © 2017)

Can this Power the world?

THE SIMPLE ANSWER IS yes. Professor Mehran Moalem of Berkley University