Solar Power Panels & Green Building in Los Angeles

In the context of structures and green construction, solar energy can be used both passively and actively.

The utilization of passive solar has to do with site orientation, location and size of windows, certain overhangs to reduce summer heat gain, planting strategy at the home’s south side, etc. Attention to orientation and windows’ placement and sizing can also help with maximizing the benefits of natural light in the home. In colder climates where retaining heat is a major concern, passive solar strategies may also include the utilization of heat storage via a thermal mass.

Active solar systems are used to heat water in lieu of (or in addition to) a water heater for home use or for the pool (so as to extend the swimming season and thus the use of one’s pool). Active solar systems can also be used to heat interior space. Solar Power systems that are used to generate electricity (Photovoltaic or PV systems) are active solar systems as well.

This article deals primarily with Photovoltaic systems (PV), which convert the sun’s energy to electrical current.

A solar power system is comprised of PV panels, which in turn are comprised of PV cells. These cells utilize a semiconductor (typically silicon) to generate electricity. The cells absorb the sunlight (photons), and the absorb energy of the photons generates a flow of electrons within the material, which is essentially an electrical current. The output of a solar system is directly proportionate to the total area of its cells; i.e., the larger the area (square footage) of the panels, the more current the system would generate (all things being equal). Generally speaking, one (1)KW (Kilowatt) of produced energy would require about 100 square feet of space.

The PV system generates direct current (DC). Our appliances, air conditioners, lighting, etc. are all using alternating current (AC). Because of this, an inverter is used to convert the DC to AC. An inverter is an integral part of all PV systems. Some systems would require more than one inverter.

For optimal performance, the PV panels should be aimed towards the south and be set at an angle (in Southern California the recommended angle is 30degrees). There shouldn’t be any trees or structures obscuring the sun nor any shade, if the PV panels are to perform as designed. Most often PV systems are installed on the roof, where roofing type and age would be factors impacting the installation sequence and cost. Less common but as effective is ground installation or installation on top of trellises. The limitation here, of course, is the available space for the panels. Note though that contrary to popular belief, most systems are not designed (or rather should not be designed) to supply the entire power needs of a home. Rather, the most return on investment is achieved by sizing a PV system so that in peak use times the higher costing billing brackets are not reached.

When a solar system generates more power than the house is consuming at any given time (for example, at peak sun times, when occupants are typically at work), the excess power is fed back to the grid, causing your power meter to rotate backwards. This is called “net metering.” This is advantageous to solar power system owners as the grid in this case functions as a storage device, negating the need for batteries, thus lowering the upfront costs involved in acquiring the system. For backup power in case of a power failure though, batteries (or an emergency generator) are still needed.

To fully harness the available sun, solar panels may be mounted onto tracking devices that rotate the panels so that they “follow” the sun’s arc across the sky. This increases the system’s cost and the likeliness of future maintenance expenses because moving parts are involved. On the other hand, such facility could increase power production and the utilization of the panels’ full potential.

Unless you are motivated by purely environmental considerations, the decision to ‘go solar’ is one of return on investment (ROI). Without the available incentives from the federal and local governments, a solar system is not a financially viable proposition at this time. The entry costs involved are very high and the ‘break-even’ point (where the initial costs have been offset by the savings in the electrical bill) would take 15-20 years to reach. An unreasonable proposition!

Yet, with the very significant incentives now available, return on investment is typically 7-10 years. Note though that these incentives are not expected to last and in California are virtually being reduced continually, so if you are seriously considering a solar system for energy, you should act without delay. It has been said that the best time to invest in solar power, Los Angeles and Southern California residents will discover, was yesterday. When the owners’ share of the cost of a system is financed (special financing might be available for solar systems), the monthly payment could be lower than the corresponding savings in the electrical bill (this might not hold true for long, as interest rates rise while solar system incentives are reduced). This means that a professionally designed system purchased with currently available incentives may actually generate a positive cash flow (reduction in electrical bill is greater than the additional monthly payment). Now that makes installing solar panels—Los Angeles’ “hottest” new trend—a worthwhile proposition!

But is implementing a solar system for you?

Well, if your electrical bill is high (and it’s a fairly certain bet that it is only going to go higher), you might be a good candidate for a solar system and, in general, green building. Los Angeles and Southern California residents enjoy plentiful sun, which makes this type of energy production feasible. Ideally, you should have enough south or south-west facing roof area (or the equivalent in available ground area) to have a meaningful system. If you live in an HOA-controlled neighborhood, you should check with them before committing to a system as well. When it comes to the installation of solar systems, whether through remodeling or new construction, Los Angeles HOAs are prohibited by California law from disallowing solar systems altogether, but they can impose restrictions upon them. We recommend though, that before you go all out for a PV system (or at the same time that you do), take steps to reduce your electrical bill as much as possible. You can start by replacing incandescent light bulbs with CFL bulbs or, better yet, LED lighting. You can (and should) also improve the energy performance of your home in Los Angeles. Green remodeling practices will help reduce the amount of energy your home ‘consumes’ and improve the quality of the indoor air, among other benefits. While you may certainly find more information about green construction on our site (quite a bit is available), we would be happy to stop by and evaluate along with you what might your best, most cost-effective approach might be. 

As with so many other things in construction and remodeling, of greatest importance is the professional design and installation of the system. For that, make sure to engage LA architects and/or contractors that are knowledgeable and experienced in green construction generally and in PV systems design and installation specifically. Doing so should assure you a system that will serve you for years to come and will pay for itself sooner rather than later. It will also give you the needed peace of mind in case of a malfunction, as reliable home builders in Los Angeles will stand by their products and be there when needed.