Set up a solar power system

Set up a solar power system

Self-installing of photovoltaic solar panelling is well within the bounds of the modest do-it-yourself hobbyist.

If you are beginning your quest to implement a PV-based solar power system, then before proceeding, be sure to perform due diligence with regard to potential renewable energy incentives. These can come in the form of rebates against the cost of panelling, as well as tax incentives and loans. For a full list of renewable energy incentives in the United States, see http://www.dsireusa.org/. In some locations, the government will contribute up to 50% of the cost of parts and installation of renewable energy systems.

Ideally, one full face of the mounting surface should point towards the sun in order to maximize exposure during daylight hours. In much of the northern hemisphere, this is usually a south-facing roof. There is more flexibility regarding the position of mounting on a flat roof. Nevertheless, the ideal mounting position remains where the greatest exposure to incident sunlight can be achieved.

Prior to commencing installation, consider future growth of trees, particularly those in neighbouring lots, which, in the future, might obstruct inbound sunlight. Be sure you choose an installation site where you have current and future control over potential obstructions (for example, your ability to reap maximum return on your solar installation should not depend on whether your neighbour has lopped his trees adequately the preceding fall).

Current pricing on solar panels is quite transient so be sure to keep a finger on the pulse of the market prior to purchasing, with a range in cost from about USD 2 per Watt up to USD 5 per Watt.

Next, you will need to consider the type of mount required. Essentially, solar panel mounts come in two types: flush mounts and roof-ground (sometimes called universal) mounts.

Flush mounts are cheaper and simpler to install. However, they are not recommended for larger solar panels and they do not allow for tilting (altering the elevation or angle of the solar panel in order to maximize incident light). Installing flush mounting kits entails attaching a metal bracket to each end of the solar panel. The bracket is then attached to the roof. When mounting solar panels with flush mounts be certain to leave sufficient clearance between the under side of the panel and the roof. This will allow adequate drainage and, perhaps more importantly, it will allow adequate airflow around the panel to prevent overheating. Consult your panel manufacturer’s documentation for recommendations regarding air gaps when using flush mounts. If the panels overheat then their longevity will be markedly reduced.

Universal mounts are so called as they can be used either on the ground or on roofs. Although these mounts require more effort to install, they are ideal for larger panels or where the position of panels needs to be periodically adjusted. These mounts are best employed when they are ‘flashed-in’.

Fully flashed-in panel mounts are the preferred method as the mounts are incorporated in to the roof joists before the roof is installed. If your house is due for new shingles or roofing in the near future then, if cost permits, combining these two tasks will allow the installation of flashed-in mounts. Flashed-in mounts will eliminate the possibility of roof leaks and the increased visibility of working with the roof off will offer greater accuracy when affixing mounts to roof joists.

If you are not in a position where you can remove roofing, then you need to drill down through the roof and into the joists in order to secure the mounts. Use a stud finder to locate the roofing joists. Mark out all your mount positions before you commence drilling. You can use a laser sight in order to ensure mounts are aligned properly. After aligning the mounts with the joists, pre-drill with a pilot bit in order to prevent splitting the joists. Next, fully drill for the stainless steel lag bolts used to secure the panel mounts.

Affix the mounts and secure the lag bolts and washers. In order to ensure a sealed, waterproof installation on each mount, apply some external silicon and metal flashing around the base of each mount.

Once all mounts are secured, begin mounting the solar panelling. Depending on the size of the panels and nature of the roof, this might require one, even two, additional helpers. Gently lower the panels in to place on the mounts and hold fast by fastening mounting screws at opposite corners of the panel. Then add additional mounting screws before tightening all.

Once the panel are secured in place, wiring must be securely run through local safety standard conduits to junction boxes and fuse boxes. You must consult local safety standards in order to determine whether you must contract a licensed electrician to carry out this work, or if you perform this work yourself, the building codes to which the wiring must be installed.

In series with the solar array will be a power centre that contains additional safety circuitry including ground-fault interrupters, circuit breakers or fuses and charge controls. The power centre can be situated near the roof, or more commonly run off adjacent to the inverter. It is important to minimize the length of wire runs and to use high calibre wiring in order to minimise loss. You must consult an electrician or reference manuals in order to select a wire gauge that is appropriate to the load your solar installation hopes to handle.

Current from the power centre is fed in to an inverter. The inverter converts the DC output from the PV cell array to an AC supply that can be used for household loads. This is often stored in basements.

set-up-a-solar-power-system

In order to save electricity for when the sun is not shining, a battery bank is used. This is wired to the inverter and charge controller and stores excess charge that can be used at other times.

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