"I’m back again to write another stellar review for GAC. Last year they replaced our HVAC system; this year we circled back and had them install a home generator. This was a long and drawn out process due to the various approvals needed from Montgomery County as well as coordination with Washington Gas (which ended up not just being a simple sign off but necessitating an additional, expensive upgrade to the gas line from the street to our home). Nevertheless, GAC did a fantastic job shepherding this process over the 6+ months of waiting on stakeholders, and they were also maximally accommodating to our family’s significant constraints on time and availability (due to health concerns related to a medically fragile family member). A special kudos to Sandy M, GAC’s master electrician, who took it on personally to ensure we were taken care of all throughout this process, going above and beyond with phone calls, text messages, personal visits, etc. on behalf of my family, I want to thank GAC and am giving top marks across the board for this effort which was complex , lengthy, and ultimately successful."
"It went great! Professional, quick to call and discuss the request. What I like the most was their genuine interest in helping me fast. They gave me an estimate the same day and the job was performed in less than 48 hours. I would definitely hire Green Electric for my future requirements. Thanks Mr. Darnell!"
"On both appointments, the technicians (David the first time, Matt & Evan the second time) were respectful and honest, very well organized. And they arrived right on time. We had ceiling fans and recessed lighting installed. They kept the work areas clean. -Frank K., City of Gambrills. My wife and I are very happy with their work, and the jobs were completed in the quoted time, even early! Everything was well explained and questions were answered with the feeling that they weren't in a rush to leave until I was satisfied. We will call again for future jobs."
"I used Mr. Electric of Baltimore to install new ceiling fans and rewire the electrical switches throughout my home. The technician was punctual, very knowledgeable and the quality of work was amazing."
"Great job helping sort out the open neutral I had. I was able to get the new wire, breaker, and outlets installed so the electronics are isolated on their own circuit. Thanks again."
Horizon Services (MD), LLC, is the regions largest and most well respected plumbing, heating and air conditioning company, with nearly 600 employees serving tens of thousands of homeowners throughout Delaware, Southeastern Pennsylvania, Southern New Jersey and Northeastern Maryland. After a quarter of a century in business, Horizon Services (MD), LLC, remains fully committed to setting the industry standard for customer service, installation and focusing on things that are important to busy homeowners.
Calvert Generator is committed to excellence in every aspect of our business. We uphold a standard of integrity bound by fairness, honesty, and personal responsibility. Our distinction is the quality of service we bring to our customers. Accurate knowledge of our trade combined with ability is what makes us true professionals. Above all, we are watchful of our customers' interests, and make their concerns the basis of our business.\n
"Larry and his crew upgraded our under cabinet lighting with new LED lighting, and specialized outlet. Not only was our home and its contents treated as if they lived here, the job was done professionally. So much so, that the only issue we had was when the switch/outlet face plate screws came loose. I didn’t even bother calling Larry, I tightened them myself. The lighting is on, literally 24 hours per day since the install, with zero issues. Love these guys."
You can determine what size generator you need for a transfer switch by matching the switch to the largest outlet on your generator. Larger generators can power up to 10 circuits, while most 5,000-watt generators can provide power to six circuits. So, if your generator’s largest outlet is 30 amps, you’ll need a 30-amp transfer switch.
If you’re wondering if you can use your electric vehicle as a backup battery, it depends on whether your EV is compatible with bidirectional charging. This technology allows energy to flow both ways, enabling vehicle-to-home (V2H) backup power, vehicle-to-load (V2L) for appliances and camping, and vehicle-to-grid (V2G) to support the power grid. Compatible EVs convert stored DC energy into usable AC power, helping reduce energy costs and enhance grid stability while providing emergency backup power.
If you have a transfer switch properly installed, the generator and main electrical power cannot feed the system at the same time. However, you should still shut off the power at your main circuit breaker panel before activating the generator. If you do that, you’ll simply need to shut off the generator and reset your circuit breaker once the local power comes back on.
Here’s what you can run with different wattages and types of generators:
Portable generator:
2,000 watts can handle a large appliance like a freezer or refrigerator, plus a few smaller items like phones or computer chargers.
4,000 watts will keep two large appliances operating and a few smaller devices.
8,000 watts should power most essential appliances and other devices, including a sump pump, well pump, or your dishwasher.
Partial to whole-house generator:
20,000 watts and above will make it seem like your home’s power is still on.
Generators are safe to use as long as they are installed and operated correctly according to the manufacturer's recommendations. The most critical safety tips are to never use a portable or fuel-powered generator inside an enclosed space due to the risk of lethal carbon monoxide poisoning; always operate it outdoors where fumes can dissipate away from your home. Additionally, never attempt to connect a generator to your home’s electrical panel yourself—hire a professional to ensure the setup meets safety standards. Finally, avoid overloading the generator by not connecting more appliances than it is rated for, as this can damage your equipment or cause a fire.
The Mitchellville, MD homeowners’ guide to generator installs
From average costs to expert advice, get all the answers you need to get your job done.
The cost to install a whole-house generator in Baltimore, MD varies based on factors like generator size, fuel type, and installation complexity. Learn the typical price range and what influences your total cost.
The cost to install a whole-house generator in Washington, DC varies based on factors like generator size, fuel type, and installation complexity. Learn the typical price range and what influences your total cost.
Generators should give you peace of mind, but you’ll only get that if your installer knows what they’re doing. Learn how to hire a pro and what red flags to look for.