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  • Writer's pictureKel Galavan

Solar Panels, everything you need to know -Part 1

We had Solar PV panels installed in 2020 and almost two years on. I can safely say it was one of the best financial and sustainable moves we've made in a long time.

In this post, I will break down what is Solar PV, how the system works and the pros and cons of solar and solar panels charging electric cars. Then, I will distil the costs in the next post and give a step-wise guide from getting quotes to installation and claiming grants.

What is Solar PV?

Let's start with the basics. Solar Photovoltaics (PV) and solar thermal are two types of solar energy technology. Solar PV is the rooftop solar you see on homes, the big dark squares adorning more and more houses. As it's called, Solar PV produces electricity from solar energy, which is used to run your home and heat your water.

Solar thermal technologies use the sun's energy to heat the hot water in your immersion.

For this post, I'll be talking about Solar PV only and not thermal. Solar PV doesn't matter if it's a cold day with solar PV. It only matters if there is sunlight or not. This allows for reasonable generation on chill, bright wintery days, which would not be the same for Solar thermal. It's all about the light and not the heat right here, which suits my Irish home.

Our starting point before the Solar Panel installation

Our annual electricity bill typically averages around €1,600 per year before the installation. This amount runs our home and electric car. Although in the current climate, please bear in mind with rising energy prices, the numbers may be a little skewed for predicting going forward. But the fundamental win we are looking for here is savings in kWh. This is because every kWh generated by the panels and used in the home is one fewer KWh that must be drawn from the grid and paid for.

We also have oil heating which costs approx €1,450 per year. However, this varies depending on oil prices. I mentioned the oil here that up until the installation, our oil was the only way we heated water and the house through the radiators. We have an electric shower, but the main one runs off the emersion. So heating water all year round for showers and the radiator in winter was the most significant drain on oil in this instance.

How the Solar PV system works

Most solar PV systems are automated, saving time and money. Each Solar PV system comes with an app, and others come with an additional countertop display that sits happily on the kitchen worktop. This little guy ( our one is an iBuddy) makes it so easy to see what is happening from an energy generating vs real-time household use point of view.

The top of the counter displays a traffic light system, so it is easy to understand.

Red - drawing from the grid, i.e. we are being charged for electricity.

Green - we are generating more than we are using, the battery is complete, and the water is hot. Our electricity needs are currently being met, so the system sends the extra electricity to the grid. This is the electricity that we could potentially get paid for in time.

Amber- is my favourite. It means we are tipping away, using the panels & battery and not giving to or drawing from the grid. This, in my opinion, is optimal.

The countertop display allows you to see in real-time your energy usage.

This real-time information is a great way to work on optimal money-saving habits for solar panels. For example, if the iBuddy ( seen below, but there are many different versions of this countertop display) is green, we are using all the energy we can, and the extra is being exported to the grid. We tend to put on a wash or the dishwasher at times like this just to get the best from it. Alternatively, we are drawing from the grid and paying for electricity if red is displayed. Red occurs at night when there is no sun or if there is a heavy load drawing electricity like a kettle or cooker.

Solar Panel App

Not every system comes with this countertop display, but every system will have an app to log into and see similar information in real-time, even if you are out and about and not at home.

Image of Solar App Dashboard

The app tracks usage, electricity generated, and anything else you might need information. It allows you to see your electricity usage throughout 24 hours easily. It can be easy to track the big energy suckers in your home like the cooker, kettle and microwave.

Free hot water

The intelligent monitor on the countertop has a partner in crime. That partner is attached to the immersion and heats the water with any spare electricity the house is not using. On bright days particularly in summer, the water tank is always brimming with hot water ready for use. This means that during the summer months, oil consumption is practically zero.

Hot water unit image

The solar PV system hierarchy

When the sun hits the panels, there is a hierarchy of what happens to the electricity produced:

  1. The house needs are prioritized. All electricity is sent to service the home's current needs.

  2. The battery will be next on the list to charge if you have a battery.

  3. Heating water happens while the battery is charging. They work in tandem.

  4. Once all the needs of the house, battery and water are met, any extra is exported to the grid.

Note: Both batteries and immersion heaters can be set on timers to charge/heat. This works best if a night saver metre is installed and you have a cheaper electricity fee at night.

This is a great way to heat water and charge the battery at night at a lower rate to be used during the day. Winter is when this comes into its own for keeping costs down.

Changing Lifestyle for Solar PV technology

Technology is moving fast, and it's getting easier every day to become savvier with energy use. The new user-friendly, innovative system gives control back to the user on how and when energy is used.

Benefits of solar panels

Cheaper electricity bills

A solar PV system can save between €250-€350 per year on the average domestic electricity bill. This will make a big difference to your household running costs, allowing you to save for what matters. But, of course, if you have an electric car, this could be higher.

Improve your BER

By investing in solar PV, you will also impact the BER of your home. For example, a higher BER will add value when selling your home and help you achieve a higher sale price. In addition, it might help get a better rate if changing mortgages.

Clean energy

Generating renewable electricity also has benefits for our environment. The energy you consume will be clean energy, which reduces greenhouse gas emissions. One main reason to choose solar energy is knowing you're doing something good for the environment. Leaning on solar energy instead of fossil fuel help keep the Earth's natural resources intact for a bit longer.

Heats water.

Most systems will hook up a booster hooked into the hot water. Boosting uses extra solar power to heat the water without using oil. Essentially, for several months of the year, a home can turn off the oil altogether, creating extra savings. Although it is prudent to turn the boiler on at regular intervals to make sure it's working properly

Solar is quiet and unobtrusive.

Solar energy won't distract you with noise and size while inside your home or backyard, an advantage over traditional generators or even clean energy alternatives like wind turbines. In addition, unlike some energy delivery systems, solar PV energy is noiseless and doesn't intrude into your daily activities. In the same way, photovoltaic solar panels are visually unobtrusive.

Most homeowners choose to place photovoltaic solar panels on a rooftop where they're not necessarily visible from ground level, taking advantage of unused space and freeing up the rest of the property for enjoyment. Even installing PV solar panels is discreet and straightforward, with no interruption to your home or lifestyle while it's happening.

PV solar panels require little maintenance.

Operating costs for solar panels are minimal, even compared to other clean energy sources. This is primarily because solar panels need little maintenance, even long-term. Since there are no moving parts, there's nothing to break and no need for regular lubrication to keep things running. So instead, they just keep working on their own.

PV solar panels still power just about every satellite functioning in space today, demonstrating their long life and reliability.

PV solar systems can be customized.

Solar panels can be configured to meet your energy needs to meet them. From an enormous mansion to a modern two-bedroom house, you can design the exact system you need to generate the energy you plan to use.

Solar may earn you money in time.

The Renewable Electricity Support Scheme is an EU initiative to help Ireland reach its renewable energy targets. However, the dates and criteria have yet to be announced. Also, potentially, the reimbursable output will be capped at something like 30%. This is a lovely additional income source if it comes into being. However, installing Solar PV should not be a core driving factor.

Limitations of Solar Panels

As much as I enjoy my solar panels, nothing in this world is perfect; there are limitations.


Our winters can be long and dark with limited sunshine. So, unfortunately, there will be stretches of the year where solar PV savings aren't as high. This period primarily falls from October to March.

The initial financial outlay can be expensive.

Shopping around and taking a little time to research what is best for you is essential. Your installer will be a wealth of knowledge but not be afraid to ask lots of questions and read up yourself.

Solar doesn't work at night.

I know this might sound a little facetious, but you may not need to pay for a battery cost for many valid reasons. Therefore once the sun goes down, you are back on the grid. Although, in many ways, this can balance out as the battery is a significant outlay. If it is not required installing the panels will be much reduced. Hence lower initial cost.

You can't go 'off the grid.'

This was something I hadn't realized until after the solar was installed. For consistent electricity in winter and summer, day and night, there will be times that you will have to draw from the grid. This means you must pay the service charge, just like everyone else. Once connected, you are liable for this payment even if you never take even one unit of electricity. The service charge is approx €300 - €400 depending on tariff and supplier.

Secondly, suppose the electricity is cut off due to bad weather or maintenance. In that case, the solar system will automatically shut down, and your home will be without electricity, just like everyone else. This is a safety feature for workers on the grid network. If maintenance is being done to fix cables etc., it would be dangerous if the panel exports electricity to the grid.

Thirdly, if you are still thinking, sure, I'll get a battery and go off-grid, it'll be ok. But, chances are it won't. In summer, solar panels can produce so much electricity that even if you did use a lot and fille d the battery, heat the water etc. There might still be electricity spare. But, this electricity needs somewhere to go in the system will break. That somewhere has to be the grid for most people.

Electric Cars and Solar Panels

Most solar panel systems will not be powerful enough on their own to charge an EV without drawing on the main's electricity at the same time. A home fast charger draws approximately 5KWh a good-sized home solar system can vary from 2KWh to 4KWh. Which on the home charger will often mean drawing from the grid.

However, there are ways to manage this optimally.

Although additional costs are involved here, the easiest way is to charge using one of the newer intelligent home chargers. These chargers are designed to use excess electricity produced to charge the car.


On certain mainly sunny days, it is possible to charge using the granny or trickle chargers that draw approximately 2.5KWhr. However, this charging method means that you have to keep an eye on the weather and household use to keep the charging as low cost as possible. However, this is a great way to continually 'top-up' the car battery for free.


If the planning restrictions for the number of solar panels lift, there is always the option to add more panels and increase the system's capacity to keep up with the electric cars charging needs.


Solar panels appear to be the way of the future. While there is an initial outlay, it will not remove all electricity usage for the most part. Solar PV gives a viable alternative to fossil consumption and much more control back into your hands when it comes to energy usage in your home.

There are many pros and cons to installing a solar PV system. Still, with practice, it can drastically reduce electricity, gas and oil costs which will have a notable positive impact on your bottom line.

Check in for part 2 of this series to find out installation costs, savings and the step-by-step process of installing solar PV in your home.


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