Posted on October 31, 2014

When it comes to green technology, solar panels are the elder statesmen, having been around for decades, and the first eco-conscious piece of technology to seep into public knowledge. People old enough can remember solar panels being installed on the White House in the 1979, before being abruptly yanked down in 1986. That was partly due to philosophical differences the new administration had with energy efficiency, but they were also big, seemingly cumbersome and burdensome panels. It was still unknown by the general public how well solar could work.

Flash forward to now. Solar technology is no longer thought of as weird or space-age or hippy-dippy save for by a few rear-guard recalcitrants. Solar panels have been reinstalled on the White House with barely a mention. A recent breakthrough is making them dramatically less expensive and more efficient. When constructing or retrofitting a multi-dwelling unit, you should look into seeing if solar panels are a good way for your building to reduce costs and your overall environmental impact.

Solar pwer

Even on large buildings, it is increasingly economically beneficial to install solar power. Image from


First things first: who benefits?

When making decisions for an MDU, you have to decide as an owner-operator your overall costs versus those of the residents. If energy is included in their rent, then installing solar panels to reduce overall electricity costs is an idea that everyone can get behind. As an owner, you will lower your all-around costs and increase your profits. You may even, if you want, be able to lower rent, which can make your building even more attractive.

However, if everyone pays for their own energy usage, the incentives for an owner/operator begin to diminish. It isn’t that they don’t want their residents to pay less but that only using solar for common areas might not match the costs of installation. You reduce your costs there, but not enough to pay for the retrofit.

However, there are some ancillary benefits you can take into account. The first is publicity and attractiveness. People love ecologically-friendly buildings and are more likely to move into them, possibly at a higher cost, especially if their energy costs will be lower. You can attract more residents, usually at a higher income level.

Second, there are other ways to disperse the costs, most notably in water heating. Every one of your residents is going to take a hot shower nearly every day, and use water for dishes and other cleaning. That water has to be heated, and as often as not, the owner/operator swallows the cost of the hot-water heater. Using solar power to heat this water can dramatically reduce a larger hidden cost.

Photovoltaic cells

How a photovoltaic cell works. Image from


How much will you save?

The answer to this question depends on how much solar power you wish to use. It is instructive to take a look at some major MDUs that have installed solar.

Singapore’s Zero-Energy Building is a massive solar retrofit whose photovoltaic cells “generate about 207,000 kWh of electricity annually–enough power for 45 four-room apartments/flats.” Once the costs of installation are complete, the owners can start saving money immediately. They expect to reduce energy costs by as much as 80%, which will quickly recoup the costs of even such a massive project.

Maybe more directly relevant is this huge multi-unit apartment complex in Los Angeles, which finished a complete solar retrofit this year. By the end of the year, Goldrich and Kest, the real estate firm that owns the buildings, is projected to make back a full 84% of the cost of installation, and by next year to be in the black.

Of course, these are huge projects. You may think that even if you wanted to take this on, you don’t have the capital outlay. However, that may not be the case–solar is expected to reach price parity in almost 40 states by 2016. It could be cheaper than fossil fuels shortly thereafter. The International Energy Association even predicts that it will become the dominant source of energy by the middle of the century.

As the cost of photovoltaic cells continues to plummet, and as solar becomes more and more efficient, it makes sense to get ahead of the game. You can attract residents, lower your costs, and be a more ecologically-responsible and sustainable MDU.

Aerial Electric specializes in the electrical aspects of MDUs, including design-assist, all the way to implementation. To find out how we can help your construction or retrofit project contact us today!