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Nov 06 2015

Why “Falling Back” is Bad for Solar

By Gordon Algermissen How Does Solar Power Work on a House? Your Questions Answered No Comments

With daylight savings recently ending, it is that time of year again to reflect on why “falling back” is a really bad idea. In the United States, daylight savings time (DST) was first formally adopted in WWI and again in WWII to save fuel and eventually mandated in all states in 1966. The economy and our energy needs have changed drastically since then. Contemporary studies about the energy-saving effects of DST have been mixed, with evidence suggesting that we use less energy on lighting but more on A/C. These studies fail to account for the ever-increasing deployment of solar energy modules around the world.

One of the biggest issues with the mass adoption of solar photovoltaics is the mismatched solar energy production with grid demand. If daylight savings time was year-round, solar energy production would be more aligned with peak-demand because the sun would be out later in the day when energy demand is higher. The duck curve below highlights the increasing importance of when solar production is highest. The more we can shift the curve to the right during the winter when DST is not in effect, the more solar energy is produced during demand hours.

When the sun is out “later” in the day as people come home from work and turn on their appliances, the sun will be powering the solar panels. Permanent DST would better facilitate the transition of energy sources for the evening electricity demand ramp up. This also means less demand for fossil fuel consuming electricity production during the evening ramp up, improving our air quality.

Unrelated to solar, with permanent DST workers get to leave work more often with some daylight still left. Studies have shown that when people leave work with the sun still out, they are more likely to socialize, purchase goods, watch less TV, and generally be more active. “Falling back” during the winter is an antiquated system that serves little purpose for the modern economy. It’s time we made daylight savings time year-round.

Nov 03 2015

Love0

Solar Energy Storage 101

By Sam Baker How Do Solar Batteries Work? No Comments

Storing energy generated from your solar panels is an effective way to make your home more sustainable. By saving energy from the daylight hours you’ll be less dependent on the power grid and even protected in case of a blackout. Let’s take a look at the technology and some of the recent advances in the field of solar energy storage.

How It Works

The solar panels on your roof generate a DC current. In a regular setup, this energy gets sent directly to a solar inverter. This device is a mandatory part of any solar panel system. It takes the DC current and converts it into an AC current that can be used by the appliances in your home. When your energy needs are high, the entire DC current is used by your home.

If you have a battery storage system, your setup will work differently. When the appliances in your home are switched off and the electricity demands are low, some of the DC currents will be diverted from the inverter and used to charge your backup battery. This process is automatic and depends on how much energy your home requires at any given minute. Because of how it’s regulated, a battery backup system is a smart choice. It only charges when your home doesn’t require all the energy available from the solar panels.

When you’re planning the installation of your home battery system, you should figure out how much storage capacity you need. A single, average sized battery will provide your home with enough electricity for a single evening. If you want something more robust, you can install a battery bank. A battery bank is a system of connected batteries, and it may provide enough electricity to power your entire home for three to four days. While this is a nice feature, many people consider it unnecessary, especially since blackouts in America rarely last more than a few hours.

The Benefits of a Battery Backup System

The biggest benefit of a battery backup system is that you’ll always have a constant supply of energy to your home. This can be an advantage because electrical rates from the utilities tend to be higher in the evening. By saving power from the day you’ll be able to use it at night and save on your bill.

Additionally, if you have enough solar panels and a large enough battery bank, you’ll be able to use renewable energy around the clock. You’ll never have to pay for electricity from the grid, which is a major incentive for some people. Using 100% renewable energy may not be a feasible option for everyone, but it’s more affordable now than it was just ten years ago.

Different Kinds of Batteries

If you’re ready to install a solar energy battery backup system, then you have a choice to make. There are two different kinds of batteries on the market, and you want to make sure that you pick the one correct for your home.

Lead Acid Batteries

These have been used for decades in various applications. They’re the cheapest option and have a proven record in providing reliable storage to homeowners. However, you should be aware that you may need to perform maintenance on the system. Flooded lead-acid batteries will require you to “water” them, equalize the charge, and keep the terminals clean. This maintenance isn’t extensive, but it might not be a good fit if you’re away from home often or prefer to buy a “set it and forget it” system.

Two other types of lead-acid batteries: gelled electrolyte and absorbed glass mat (AGM) are maintenance free. These batteries are more expensive though and they also require voltage regulated chargers.

Lithium-Ion Batteries

These are the type of batteries that are found in your cellphone, and they’re the most common battery in the world. Lithium-ion batteries are more expensive than lead-acid batteries. However, they typically last longer and they have a high discharge and charge efficiency. That means they’ll be able to store the DC current from your solar panels more effectively, losing less energy in the process.

One of the most exciting new technologies on the market (or soon to be on the market) is the Tesla Powerwall lithium-ion battery. Much like an Apple product, this new solar storage battery combines form with function. It’s small, easy to install, comes with a ten-year warranty, and it’s even beautiful to look at.

Hopefully, this new battery from Tesla is just the start. In the coming years, we may see an influx of new solar energy storage batteries which will be more efficient and have a lower price tag. This will make it more feasible for homeowners to generate electricity from their solar panels and store it for the evening and night. If you still don’t have solar panels on your home and would like to find out more, contact Solar.com today and see how you can make your dream a reality!

Sources

http://bosch-solar-storage.com/the-battery/lithium-battery/

http://www.solarpowerworldonline.com/2015/08/what-is-the-best-type-of-battery-for-solar-storage/

http://www.teslamotors.com/powerwall

http://www.energymatters.com.au/residential-solar/battery-storage/

http://www.wholesalesolar.com/solar-information/deep-cycle-battery-info