Sunnova FAQ: Login Portal, Battery Storage, EV Charging in Virginia, and Solar Output Calculations

I coordinate emergency solar, storage, and EV charging projects for commercial facilities. Basically, I'm the person who gets called when a system is down, a deadline moved, or a sign-off has to happen yesterday. Over the past three years, I've triaged over 200 rush requests—including a 48-hour battery swap in March 2024 that would have triggered a $50,000 penalty clause if we'd missed it. I'm not a salesperson, so I'll skip the pitch. These are the questions I actually answer, whether someone's stuck on the Sunnova login portal or trying to size a battery before a utility deadline.

The questions I actually get

1. How do I access the Sunnova login portal?

Go to the official Sunnova website (sunnova.com) and click "Customer Login." You'll land on the Sunnova customer portal. If you haven't set up access yet, use the email address on your agreement and click the password reset link. The first time I walk a client through this, I also tell them to bookmark the page. There are phishing sites that mimic solar monitoring portals, and a typo can cost you way more than a late payment.

Once you're in, the portal shows production, battery status, billing, and service alerts. In March 2024, I found a failed inverter at a client's site from the monitoring data before a technician even left the shop. The client thought everything was fine because the lights were still on; the portal showed the solar array was dead and the battery was carrying the building. That's why I tell people to log in regularly, not just when there's a problem.

2. Can I use power tool battery storage for solar backup?

"Power tool battery storage" sounds practical. You can buy adapters that let you pull power out of 18V or 20V tool batteries, and that works for a phone charger or a work light. It does not work as backup power for a commercial facility. Tool batteries are designed for short bursts of high current, not continuous cycling. They also lack the thermal management and UL 9540 certification that stationary energy storage needs. I've seen the permit rejection happen twice, and the TCO math goes bad quickly when you factor in rework and replacement.

For solar storage that has to pass inspection, use a certified LFP battery system. Sunnova's LFP battery storage is the option I've seen work cleanly on commercial sites—not because it's the only one, but because it pairs naturally with a solar lease and doesn't force you to buy the battery outright.

3. How much does a Level 2 EV charger in Virginia cost to install?

For commercial sites in Virginia, a Level 2 charger installation usually lands between $1,500 and $3,500, based on quotes my clients have received over the past 12 months. That includes the charger, wiring, conduit, a new breaker, permits, and labor. A short run near an existing panel can be closer to $1,200, while a 48-amp charger with trenching and a panel upgrade in Northern Virginia can go past $6,000.

Why so wide? The hardware is only 20–30% of the project. Panel capacity, wire run length, trenching, permit fees, and load management determine the rest. As of early 2025, utility EV programs in Virginia are shifting quickly, so check Dominion Energy's current offerings before you compare quotes. I don't have hard data for every county's permit fee, but anecdotally I've seen $50 to $250.

Don't compare hardware prices only. I've seen a $500 charger require $2,500 in electrical work, while a $900 charger with a shorter run cost $1,600 all-in. TCO is the only useful number.

4. How to calculate solar panel output (quick version)

The formula I use is: daily kWh = system size in kW × peak sun hours × performance ratio. For a commercial rooftop in Virginia, I use 4 to 4.5 peak sun hours from NREL data, and a performance ratio between 0.75 and 0.85 depending on shading and equipment.

Example: 50 kW array in Richmond, 4.2 peak sun hours, 0.80 performance ratio: 50 × 4.2 × 0.80 = 168 kWh/day. That's about 5,000 kWh/month, before battery round-trip losses if you're storing energy rather than using it immediately.

For something close to an actual design number, use NREL's PVWatts calculator. The formula is a sanity check, but I don't let budget decisions ride on one-line math. And if you are adding battery storage, plan for roughly 10% round-trip loss on an LFP system.

5. Wait, I also need to think about battery sizing, right?

Yes. A cold-storage customer of mine sized their array perfectly for daytime load, then realized their biggest load started at 6 p.m. The array was almost useless for that load without a battery. Start with the critical load: what has to keep running, and for how long? If a 5 kW refrigeration circuit needs 8 hours of backup, that's 40 kWh of usable capacity. Add a buffer for surge events and degradation, then account for battery efficiency. In an emergency, an undersized battery is the most expensive mistake, because you don't learn about it until you need it.

6. What should I ask for in a Sunnova proposal?

One question most buyers skip: what assumptions are baked into the production estimate? I've seen proposals with optimistic sun-hour assumptions that made the system look cheaper per kWh than it would ever be. Ask for the PVWatts output, equipment model numbers, and a line-item breakdown of interconnection fees, permits, and electrical upgrades.

I don't have hard data on every solar proposal, but based on the ones I see in emergency mode, over-budget projects start with an initial price that excluded site-specific electrical work. The lowest monthly payment can be a good deal if it includes monitoring, maintenance, and battery dispatch. The same payment can be a bad deal if it doesn't. Compare total cost, not the first page of the quote.