With the cost of a solar system going down and down, you may be considering converting your home to solar energy. In addition to moving us all one small step closer towards leaving fossil fuels behind, it can make a lot of sense from a financial perspective. Depending on your location and the solar potential of your home, you could see anything from a reduction in your energy bills to a small income for power sent back to the grid.
The upfront costs can be significant, however, and recouping those costs will be a long-term investment. If you’re really trying to do this on a budget, you might consider a DIY installation.
This article will walk you through some basics of solar panel equipment: what you need, what it all is, and what installing it might entail. Even if you plan on hiring professionals to install a system for you, it definitely never hurts to get familiar with the equipment that’s powering your home so you know how it all works.
Your panels are the workhorse of the operation. Solar photovoltaic (PV) panels are made up of individual solar cells. They capture photons from sunlight, which bounce around in the semi-conductive materials that make up these cells, knocking off electrons and generating a current that, once inverted, powers your home.
You’ll have a choice between monocrystalline, polycrystalline and thin-film, or amorphous, solar cells. Monocrystalline silicon cells are the most efficient and heat-tolerant, which makes panels made with them smaller and therefore easier to install, but also more expensive. Thin-film cells are the least efficient, while polycrystalline silicon cells are less efficient than monocrystalline but less expensive, making them more popular.
There are some key calculations you’ll need to make in terms of energy load and system size in order to choose the right solar panels to do the job. There are many online calculators that will help you determine the size you need—NREL’s (the National Renewable Energy Laboratory) is excellent.
Panels can be ordered individually, but many manufacturers offer them in kits. While panels will all differ in terms of physical size, efficiency and materials, the installation process for the DIYer will be similar.
Once you’ve chosen your panels, you’ll need a frame to mount them to the roof. On rooftops, this frame is called solar racking. The racking attaches the panels to the roof and also angles your panels to get the most exposure and therefore the most power.
The average roof will be able to use a fixed roof mount. As the name suggests, these types of mounting systems can’t be adjusted to follow the sun, but they’re the most straightforward to install. Racking is composed of metal rails (usually aluminum) that work like brackets to hold up the panels. The panels are clamped to the rails, which are affixed to your roof with mounts that are secured to your rafters.
For those with low-angle or flat roofs, mounts with tilt legs might be necessary. These legs allow you to prop the panels up in a more upright position and adjust them to receive the sun’s rays as directly as possible.
Since you’ll be drilling through your roof to affix the mounts, you’ll also need some flashing to protect your roof.
You may have the space for a ground mounted array instead. Although they’re more expensive and require considerably more space, they’re also more productive. Homeowners can use more, and larger, panels and have greater flexibility in terms of positioning them to face the sun.
The most common types of ground mounted arrays are fixed arrays, where the panels are fitted to a metal frame at a fixed angle, or a pole mounted array, which allows for some adjustability. Both of these options will require foundations or footings as part of their installation.
Your solar system will convert sunlight into DC (direct current) power. Your home, however, is most likely to be set up on AC (alternating current) power, so you need an inverter to turn the power your system generates into usable energy.
There are a few different options for inverters. String, or central, inverters connect all your solar panels as a whole to your home’s electrical panel. These inverters are more straightforward to install and less expensive, since you’ll likely only need one (maybe two) of them.
Since they treat your panels as one single power source, the performance of the entire system will suffer if there’s an issue with a single panel (for example, if a panel becomes shaded). The electrical current can only be as strong as the weakest panel, so the available power can be dramatically compromised by even a single underperforming panel. There are ways to wire around this issue, but it’s something to consider.
Micro-inverters, on the other hand, invert power at the site of each individual solar panel. These are a more expensive option, but they’re also more efficient. If there’s an issue with one panel, that issue won’t affect the power that the rest of the system has generated.
Power optimizers compensate for the losses that can arise with a string inverter. They’re used with string inverters, but function as a bit of a hybrid between the above two types of inverters. They’re connected to each individual panel, but rather than convert the electricity at that point, they optimize the voltage of the DC current, which is then sent on to a centralized inverter. Cost-wise, they occupy a middle ground between the other two.
Like micro-inverters, these have the benefit of allowing homeowners to monitor the performance of each panel and to spot problems on an individual scale.
Solar monitoring systems give homeowners important information about the efficiency and output of their panels. They pull information from the inverter(s) and offer real-time performance tracking, as well as historical data. These systems can inform you of potential issues with panels and offer guidance on troubleshooting.
If your system is off-grid, the monitor can also give you information on the charging state of your batteries. A system can be on-site, through a wired-in monitoring device, or cloud-based, so you can check from anywhere.
You already know what these are. Those who are going off-grid have a lot to consider when it comes to batteries, though. The battery’s capacity, its power rating, its efficiency, its expected lifespan and its depth of discharge (or DoD, i.e. the amount of battery you can drain before you really should recharge it) are all key considerations.
Batteries can be made of lithium ion, which is popular because of its longer lifespan but also more expensive, or lead acid, which is cheaper but doesn’t last as long. If you opt for battery storage, you’ll also need a charge controller to regulate the current going into your battery and ensure it doesn’t overcharge or over-discharge.
These are the basic component parts of a solar system. These systems could be slightly simpler or a good deal more elaborate, but we hope this gives you some idea of the things you’ll need to get started on your DIY installation.