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Six Things to Consider Before Installing Solar Panels

Things to consider before installing solar panels

Here are 6 things to consider before installing a solar panel:

    • Step 1: Choose the right technology
    • Step 2:Measure your energy use
    • Step 3: Check your local financial incentives
    • Step 4: Decide the correct positioning
    • Step 5: Decide if you want a battery
    • Step 6: Choose a good installer

The low cost of solar energy means that there is a growing number of both businesses and households installing their own solar panels. Reducing energy consumption from the grid and switching to producing one’s own energy via solar technology can bring significant savings on electricity bills or even help you go off-grid entirely.

Whether you are in charge of a business or a household, if you are looking to ‘go solar’, how can you actually go about installing solar panels?

This can usually be done by a dedicated solar installer. However, it is important to be informed so you can find an installer who will provide you with the best investment. Here are the main steps you should expect.

Step 1: Choose the right technology

Solar panels

There are multiple types of solar technology to choose from. Solar thermal for example allows you just to heat water, whereas photovoltaic allows you to produce electricity.

Within photovoltaic systems, the two main options are monocrystalline and polycrystalline silicon. Monocrystalline silicon panels can provide slightly higher efficiencies than polycrystalline, however, the various other factors, explained below, usually greatly outweigh the benefits of choosing monocrystalline over polycrystalline.

Choosing a reputable brand of solar panel will have a much larger impact on the energy your system will generate.

Water boiler with solar panels on roof of house
Solar water heaters also called solar domestic hot water systems can be a cost-effective way to generate hot water for your home.

Inverters

The solar system doesn’t just consist of the solar panels but an inverter too. This device converts the direct current (DC) produced by the solar panel into alternating current (AC), a form of electricity which can be more widely used. There are two types of inverters.

The first is the string, or centralised, inverter. This is the most common inverter used around the world. It is usually more cost-effective and converts all DC power from the solar panels centrally. The disadvantage of this is that it treats the solar panels like Christmas lights: if one panel is underperforming it limits the whole setup. The solar installation is only as efficient as the weakest panel, meaning if one panel is in the shade the whole system generates less electricity.

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The second type of inverter is the microinverter. This costs a little more than the string inverter yet has some advantages. Unlike the string inverter, the microinverter is usually mounted on each individual solar panel. This means that it is much more tolerant of shade, allowing more energy to be generated from a partially shaded solar array.

Choosing a good quality inverter is very important, as they are usually the limiting factor for any solar array. The inverter will usually be the first component in the setup to reach the end of its lifetime. Inverters last in the range of 15 years, whereas the solar panels themselves last around 30–40 years. If you are unsure whether to shell out more money for a premium solar panel or a premium inverter, go with the premium inverter.

A solar micro-inverter, or simply microinverter, is a plug-and-play device used in photovoltaics, that converts direct current (DC) generated by a single solar module to alternating current (AC).

Step 2: Measure your energy use

A good solar installer will help you measure your energy use. This is important to determine how much energy you want to generate with your solar system. By knowing the average amount of energy you will be consuming, you can make an informed decision on how many solar panels you want to install and how much of your energy consumption can be covered by solar.

Also important is when you use energy. In the mornings and evenings or in the middle of the day? This is important when considering the positioning of solar panels and in the importance of feed-in tariffs and net metering to you.

before installing solar panels, measure your current energy use
To determine your home’s average energy requirements look at past utility bills. You can calculate how many solar panels you need by multiplying your household’s hourly energy requirement by the peak sunlight hours for your area and dividing that by a panel’s wattage. Use a low-wattage (150W) and high-wattage (370W) example to establish a range (ex: 17-42 panels to generate 11,000 kWh/year). Note that how much sunlight your roof gets and factors such as roof size and battery storage will figure in as well.

Step 3: Check your local financial incentives

In many countries, governments provide incentives to those wishing to install solar panels. The aim of this is to allow electricity generated from photovoltaics to compete with established energy production methods. Government financial incentives can come in various forms, with the two main ones being

  • Investment subsidies, in which the cost of installing solar panels is partially refunded.
  • Feed-in tariffs or net metering, whereby the solar electricity you produce can be sold to the electricity utility operating the grid.
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Subsidies for solar PV are provided in numerous countries, for example, Germany, India, China and the US. Feed-in tariffs are perhaps even more popular, with countries adopting the policy including Australia, Canada, many EU countries, China, South Korea, Taiwan, UK and the US.

Often, countries offer both of these policies, while in some countries other incentives also exist (such as Solar Renewable Energy Certificates in the USA).

Finding out about your local financial incentives can be a major deciding factor on whether installing solar for your home or business makes financial sense.

Step 4: Decide the correct positioning

Where to place your solar panels can have a much greater effect on the amount of electricity generated than, for example, choosing monocrystalline or polycrystalline panels.

Direction – north, south, east or west

  • If you live in the northern hemisphere, the sun is in the south of the sky. Therefore, for maximum exposure to the sun, solar panels can be placed on a south-facing roof.
  • Likewise, in the southern hemisphere, solar panels are best placed on a north-facing roof.
  • However, if you don’t use much energy in the middle of the day, as with most homes, and instead most of your energy use is in the evening, a west-facing solar array might be more useful.
  • If, however you prefer more solar electricity generation in the mornings, an east-facing direction would be preferable.

East and west-facing solar panels, of course, generate less energy throughout the entire day than those facing towards the equator, however, unless you intend to install a battery or feed-in tariffs are available where you live, this can result in more optimised usage of your electricity.

There is a difference between magnetic south and true south that must be considered. Magnetic south is the "south" shown when a compass is used, and this south points to the Earth's south magnetic pole. Solar panels, however, need to face solar or geographic south, which is the direction towards the South Pole.

Angle – to tilt or not to tilt?

Solar panels can also be tilted towards the sun using tilt frames. The best angle to tilt a solar panel is directly defined by the latitude where the solar panel will be installed.

Optimising the tilt angle does result in a few per cent increase in efficiency and therefore slightly more electricity generation. Depending on the tilt angle of your roof, however, the added cost of a tilt frame may not be worth it. Most roof tilt angles are more than sufficient to provide adequate electricity generation. If however, you have a flat roof, tilt frames may indeed be worth the extra cost.

Installing solar panels on the roof
Solar panels or PV arrays are most efficient, when they are perpendicular to the sun's rays. The default value is a tilt angle equal to the station's latitude plus 15 degrees in winter, or minus 15 degrees in summer.

Step 5: Decide if you want a battery

For home solar PV installations, the time at which most electricity is generated, during the middle of the day, doesn’t usually coincide with the time at which most electricity is consumed, in the morning and evening. In fact, most electricity is consumed just after the sun sets, when televisions, air conditioning, heating and kitchen appliances are used most.

Therefore, both from a financial environmental perspective, it seems logical to store energy during the day with a battery to be used in the evening.

The truth, however, is less straightforward. Batteries can be expensive compared to the savings they can potentially provide. Each individual case is different, but batteries can take many years to pay themselves back in the savings they provide. With most batteries having a guarantee of around ten years, if it takes more than ten years to pay itself back, a battery is probably not worth the investment, as it may well be likely to fail beforehand.

The environmental impact of batteries is a complex topic. Batteries do often enable the greater use of renewable solar energy. Yet the production of batteries can be a source of more carbon emissions than they will prevent being used throughout their lifetime. Added to that the environmental impact of the mining of their raw materials, most batteries, such as lithium-ion, do not, in reality, fulfil the expectations of most consumers.

With newer emerging technologies such as redox flow batteries, and falling prices, things are likely to change for batteries, so keep an eye on prices, and guarantees.

Step 6: Choose a good installer

Last but not least, once you are well informed on the above topics it is important to choose a reputable installer that will:

  • inspect your specific situation
  • advise you on the ideal technology and installation
  • obtain the required permits and paperwork
  • perform the installation
  • ensure all of the correct connections.

Importantly, installation can usually only be carried out by certified professionals. As with any service, choose one that is reputable and can meet your expectations.

Installing your own solar panels has the potential to allow you freedom from the electrical grid, reduce the carbon footprint of your household or business and possibly reduce your electricity bills.

To learn more about the various types of solar panels and the various costs associated with installing and maintaining solar panels, make sure to read our next article: Types of solar panels and how to choose one.

"I am keen for readers to look at materials with the same fascination I do and to see how they will impact our future."
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*This article is the work of the guest author shown above. The guest author is solely responsible for the accuracy and the legality of their content. The content of the article and the views expressed therein are solely those of this author and do not reflect the views of Matmatch or of any present or past employers, academic institutions, professional societies, or organizations the author is currently or was previously affiliated with.

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