Solar Energy Solar Panel Washington DC Solar
Written by Roger Perry

Practical Considerations for a Battery System

As long as I’ve been doing solar, people have been asking about batteries. The response has always been “yes, we can do them, but it will cost a lot”. That usually ended the conversation.

One question to ask is “why do you want batteries?” Do you lose power frequently? If not, a portable generator will keep your refrigerator, freezer, computers, tv and some lights going. Downsides are; noise, fumes, refueling, having to run extension cords to where needed and putting everything away when power comes back. Not too bad once in a while and it’s very cost effective. Just hope you aren’t out of town when power goes out. There is nothing automatic about this set-up.

If you lose power often and don’t want to do the portable generator dance every few months, you can get a permanently installed generator with automatic start. These are close to $5000 installed for the ones that will run most of your house when the power goes out (a larger one can be installed for a few thousand more that will run everything). This is what hospitals and critical buildings use. Power goes out, the generator starts automatically and powers the house with only a momentary loss of electricity.

Downsides? Noisy, they need maintenance and, if propane or diesel powered, they need the fuel tanks to be kept filled.

What if you lose power often, don’t want the noise, maintenance and fuel expense of a generator? What if you want a system that is environmentally friendly, will turn on automatically, is silent, will run pretty much nonstop without refueling? You should look into installing a battery back-up system connected with a solar system.

What are the downsides? Well, cost is one. While not as expensive as in years past, battery back-up systems are still costly. Compared to a permanently installed generator, battery backups tend to run few thousand more. Ask your accountant but you may be able to take the 30% solar tax credit on the additional cost of the batteries. This brings the price in line with a generator.

Another downside is you can’t run everything in your house. Things a battery cannot run for any length of time are air conditioners or heat pumps, electric water heaters, electric dryer or electric ranges. What they can run are gas or solar water heaters, gas or oil boilers, refrigerators, freezers, lights, tvs, computers, fans and pretty much everything else. Well pumps are on the edge depending on how efficient they are. While running a modern variable speed well pump is not an issue, older well pumps require a large startup current which can be too much for the battery to handle. We are about to install a “soft start” control to try and reduce a well pumps surge demand for one of our customers but the jury is still out.

We are now installing LG Chem lithium Ion batteries. LI batteries have a lot of advantages over the old lead acid batteries. The big advantage they have is they are not damaged by running them dead, whereas lead acid batteries do not like being discharged to less than 50% of charge, a Lithium Ion battery will give you it’s full rating. The one we use is rated for 10 Kilowatthour (KWH). A lead acid battery would need to be rated at 20 KHW to achieve the same capacity. Lithium batteries are also much lighter (not that the customer will have to move them) and can be charged much faster.

The big downsize of LI batteries is the upfront cost compared to LA but they will last much, much longer and they are maintenance free.

In a future blog I will discuss the two different ways to interface a solar system with the batteries, AC coupled and DC coupled and the pros and cons of each as well as what a 10 KWH battery will give you as far as run times for various appliances. I’ll also talk about how a battery system can be retrofitted to your existing solar system.

Electric Charging, Solar, Annapolis MD
Written by Lisa Walsh

Solar Systems with Integrated Electric Vehicle Chargers

….like Peas and Carrots

Solar Panel, Solar energy, Annapolis MDAs referenced in our accompanying EV Growth Blogs, the adoption of Electric Vehicles has skyrocketed in recent years. This is small wonder considering EV purchasers can look forward to a 30% federal tax credit on the upfront cost, reduction of fuel costs of at least 60% (according to this Nissan Leaf owner’s calculations), and State Grants/tax credits where applicable (Maryland, for example) and the negation of various oil changes and maintenance costs that accompany an internal combustion engine. For homeowners who have discovered the substantial energy savings by purchasing (not leasing!) a solar residential system, it’s a natural step to want to extend these savings to their current, or future, electrified vehicle.

Ahead of the curve on this natural progression is an innovative new product from inverter manufacturer SolarEdge. All solar systems have two major components 1. Solar panel arrays 2. Inverter(s) that convert incoming DC energy to appliance-ready AC energy. As the national leader in residential inverter supply, SolarEdge made a great move in developing an Inverter that has a built-in EV Charger with a 25’ charge connector. Net energy meter customers (NEM) or energy generating customers interconnected to Pepco are not eligible to apply for the R-PIV rate.

Electric Charging,Solar, Annapolis MD

Why not choose a separate EV Charger?

Four reasons:

  1. Cost. Upgrading to an inverter that has a built-in EV Car Charger comes at around a $1000 cost increase (assuming one inverter/car charger). However, this upgrade – as part of the solar installation – qualifies for the 30% federal tax credit, putting the material cost at around the same as a separate stand-alone EV Charger such as Clipper City. In addition, the integrated inverter has no additional labor or electrician charges – its all covered in the solar install.
  2. Warranty. Popular stand-alone Car Chargers such as Clipper City come with a 3- year warranty. Solar Edge’s integrated inverter has a 12-year warranty, with upgrades up to 25 years available.
  3. Design Elegance. Between service panels, routers, generators and other wall-mounted electronics – its nice to have a 2-in-1 solution and save some wall space. No additional wiring or conduits needed. Of course, the inverter does need to be placed within 25’ of where the EV will be parked nightly.
  4. All Pros no Cons. As with Stand-alone chargers, Solar Edge’s integrated solution allows for indoor/outdoor placement, comes with a 25’ connector and offers software that tracks your EV’s energy consumption that is accessible from desktop or phone, and can be controlled remotely.

Thinking Ahead

Due to the clear advantages, and seeming inevitability of rapid EV adoption by the majority of Americans by the Year 2030, we now ask all of our prospective solar shoppers two questions:

  1. “Do you plan to buy an Electric Vehicle in the not-so-distant future?”
  2. If so, “ What is your expected weekly/annual mileage?”

Mileage calculations inform how many solar panels we should add to the array in order to cover as much EV car use as possible (as roof space allows). Worth noting for our Washington DC/Montgomery County solar customers, PEPCO does require us to fill out an Electrical Usage Calculation Sheet if the solar system is sized over 120% larger than the past 12 months usage history. In those cases we simply submit the estimated kWh increase (as per expected mileage calculations) that the EV will add.

Written by Lisa Walsh

PEPCO Incentives for Electric Vehicle Owners in Maryland and DC

PEPCO has an Electric Vehicle (EV) Program for residential customers in Maryland. It is open to all qualified residents throughout the state. You can participate in the program if your electric vehicle is registered in Maryland.

This program was created to encourage off-peak vehicle charging. The benefits include lower off-peak electric rates for charging during the 16 hours of off-peak hours available Monday through Friday and all day Saturday and Sunday. This policy lightens the load and strain on the electric grid which improves the reliability for everyone. It also encourage the shift to clean energy which will reduce car emissions. And if you choose to charge your car with solar panels, you will achieve an even greater impact.

Another way you can make a difference is by shifting your energy usage to night time. Run your big appliances at night. Wash and dry your clothes at night. Run your dishwasher at night. Again, this will lower the burden on our power plants and it will also lower your electric bill too.

In DC, PEPCO is proposing special incentives to owner’s of electric vehicles. The program will offer lower electric rates to owners of EVs that charge their cars during off-peak hours. Some customers will also qualify for discounts on Level 2 smart charging stations that includes 100% of the cost of installation. For commercial property owners, PEPCO will install charging stations at a discount and they will also install them for free. PEPCO is also planning to install 20 fast charging stations along the main roads and in each Ward and in each quadrant of the city. Finally, PEPCO will be creating a $1,000,000 fund that is designed to provide grants for people and organizations with ideas that can help encourage a greater shift towards electric cars.

Let’s also help PEPCO increase electrification by considering a shift towards renewable sources from solar panels. Please contact us via this website or call us at (410) 923-6090. We have hundreds of installations throughout the Baltimore/Washington/Annapolis area. We look forward to helping you too.

Written by Lisa Walsh

Incentives for Electric and Hybrid Cars in DC

Washington DC’s government is encouraging the ownership of electric and hybrid cars with incentives that will save you time and money. For one, if you own an electric vehicle, you are exempt from emissions testing. If your car emits nothing, there is nothing to test. You simply need to register it with the DMV in DC. And if your car is a hybrid that is both electric and gas powered, you only need to pass a smog test. For questions about this, you can call the DC Department of Motor Vehicles at (202) 737-4404.

Fuel Efficient Cars get Reduced Registration Fees

You can also qualify for a discount on the first-time vehicle registration for a qualifying electric, hybrid or clean fuel vehicle. Their rules state that your car must get at least 40 miles per gallon in city driving. Check www.fueleconomy.gov to see how your car rates. You also must be the original owner of the car. If your car is used, you are eligible for the excise tax exemption. This exemption is the tax you pay upon purchase of a vehicle. So, the exemption can be a nice savings for you.

You might also qualify for federal tax credits. Eligible cars include electric, hybrid, plug-in hybrids, diesels and alternative fuel vehicles. Ask your accountant about how this might benefit you. And another benefit is that your insurance company might offer a discount. If they don’t, you might want to call around to find a carrier that does. These savings can really add up.

And finally, if your business has a fleet of 10 or more clean fuel automobiles, you can qualify for an exemption to the HOV lane. Again, call the DC DMV at (202) 737-4404 to find out about this benefit. Going electric and fuel efficient will put you in the fast lane in so many ways.

And, of course, we are always available to help you power your electric car with solar panels at your home, in your community or at your business. Please contact us if you have questions about generating most, or all, of your energy from solar.

Solar Service Home Solar Panels
Written by Lisa Walsh

Solar Energy During a Power Outage?

Not quite so cut and dry…

Solar Service ,Home Solar PanelsMost of us who live here in Anne Arundel County appreciate our proximity to the Chesapeake Bay, changing seasons with spectacular Spring and Fall temperatures, and mature wooded areas. However, these pros quickly become cons during snowstorms, thunderstorms and Maryland’s annual hurricane season from late August through October when Hurricanes such as the infamous Isabelle and Sandy blast through our wooded, watery region, bringing floods, downed trees and – the clincher – power outages. If not for the threat of the power outage, we may sit back and enjoy a hurricane as a powerful force of nature, so long as our lights are on, heat or ac is blasting, and refrigerator’s chilling.

Hurricane Sandy caused around 300 thousand power outages here in Maryland, with an estimated 60 thousand in Anne Arundel County alone. It’s a no wonder that many prospective solar system owners – as well as existing solar system owners – want to know if a solar power system can power any of their appliances during a power outage, even if only while the sun shines. Unfortunately, it’s not that simple.

For both functional and safety reasons, there are several additional complexities to a “hybrid” PV system that connects to the grid but also provides backup power during a power outage. To start, during an outage you need to be able to safely isolate your “solar generator” from the grid to protect the line workers. You will also need energy storage (batteries) to balance solar energy supply and household demand. In most cases, you need an additional inverter to convert the batteries’ DC electricity back to AC electricity for your household. Lastly, most battery systems require some level of maintenance as well as replacement one or more times in the lifetime of the solar system. The bottom line is that unless you are willing to pay a nominal 30% premium for a solar system that includes the necessary batteries, transfer switches and additional inverter(s), you might be better served with a more traditional approach to backup power, like a gasoline or natural gas generator, and possibly just for critical loads.

Don’t get me wrong. Hybrid systems are growing in numbers and technology advancements, consumer demand, and smart grid capabilities all will help to drive down costs to make these systems more affordable in the future, ideally making our grid more stable with many distributed sources of energy. In the mean time, most solar installers can offer a hybrid (battery backup) or traditional generator back up options, so you can decide what suits you best.