Solar is not only a very reliable and lasting energy source but also a very cost-effective and efficient one. Choose a type of solar panel that fits in your environment. Given the constant supply of sunlight all year round in most countries, it is one of the reasons why solar energy is preferred for OffGrid projects. Producing solar energy does not have any negative effects on the environment. It does not release any greenhouse gases, toxins or other waste. The traditional forms of energy such as fossil fuels are infamous for their carbon emissions and toxins. With solar energy, there are very minimal environmental impacts. Solar energy has become popular and widespread over the last years. As such, there are many solar companies that offer installation and maintenance. Solar systems are easy to maintain compared to other energy sources. Once the installation is finished, the only work needed for the solar panels is regular cleaning of the panels to remove dust, snow, kangaroos and whatever else could be on the panels. The presence of the sun means that there is a constant source of solar energy that cannot be exhausted. Solar is definitely a desirable source of energy for OffGrid living.
Plug and Play / Plug-In / Mini – Solar Systems
This type of solar systems is used for houses with electric grid connection.
These small photovoltaic systems are often also called mini-solar systems, plug& play solar systems or balcony modules, because they can be mounted on the balcony for example.
However, this is not a “plant” in the technical sense, but rather a household appliance that generates electricity.
The power from the plug-in solar device flows, for example, into the socket on the balcony and from there to the TV, refrigerator and computer, which are plugged into other sockets in the apartment. The electricity meter rotates more slowly. If the electricity from the balcony is not sufficient for the operation of the household appliances, electricity simply flows from the grid.
Without a grid connection, these solar systems do not produce electricity.
Plug solar devices usually consist of 1 or 2 solar modules and an inverter.
In contrast to photovoltaic systems, the much smaller plug-solar devices are designed for private individuals to install, connect and use them themselves.
With a plug-in solar device, you make your own personal contribution to the energy transition. The mini-solar systems usually produce enough electricity to cover a significant part of the base load and the midday peak of a household.
The first step in designing a solar system is to find out the peak power in wattage and energy consumption of all loads that need to be supplied by the solar system. Add the Watt-hours needed for all appliances together to get the total Watt-hours per day that must be delivered to the appliances. Multiply the total appliances Watt-hours per day times 1.3 (energy lost in the system) to get the total Watt-hours per day which must be provided by the panels. To put it simply: If you have only 1000watts of solar panels but you run a device that will consume 1500watts the spare power will need to come from the battery. If you use more energy then your battery and solar can provide the inverter will cut the power after the battery is empty.
There can only be basic guidelines on the dimension of panels to battery as this depends highly on your location, energy consumption habits, sun hours and more.
Tips for dimensioning a solar system
- Always size for the bad times of the year, never size for optimal conditions!
- In cloudy conditions with rain, expect your panels to produce only 5-10% of their optimal wattage. If you expect to have 500Watt of incoming power from solar during these conditions you need about 5kw of solar panels.
- A good ratio of solar panels to battery size is when you have half decent conditions (some clouds, but still a bright day) your batteries should be charged within some 5-6 hours.
In good conditions your batteries should be charged within around 3 hours.
- Better too much solar panels then not enough.
Types of solar panels
Monocrystalline Panels (Mono-SI)
This type of solar panels are made of monocrystalline silicon. You can easily recognise them from the uniform dark look and the rounded edges. The silicon’s high purity causes this type of solar panel has one of the highest efficiency rates, with the newest ones reaching above 20%.Monocrystalline panels have a high power output, occupy less space, and last the longest. Of course, that also means they are the most expensive. Another advantage to consider is that they tend to be slightly less affected by high temperatures compared to polycrystalline panels.
Polycrystalline Panels (Poly-SI)
You can quickly distinguish these panels because this type of solar panels has squares, its angles are not cut, and it has a blue, speckled look. They reach around 15% efficiency rates. The industry manufactures polycrystalline solar very effectively. This contributes to the competitive pricing of polycrystalline solar panels. However, the differences between mono- and polycrystalline solar panels are not so significant. The first option offers a slightly higher space efficiency at a slightly higher price but power outputs are basically the same.
Thin-Film Solar Panels (TFSC)
The thin film panels gets its name from how it’s produced, layers of semiconductor materials rolled out as a film on a glass surface. Thin film solar tends be less efficient than crystalline solar panels, and they requires a lot of space. They also tends to degrade more quickly, and break much more easy to physical stress, so companies offer shorter warranties. Usually they are the cheapest amongst the different types.
Amorphous Silicon Panels (A-Si)
Have you ever used a solar powered pocket calculator? Then you have seen these types of solar panels. The amorphous silicon solar cell is the type of solar panel that is used mainly in such small devices.