Page 44 | Solar.com

Please enter a valid zip code.

(888)-438-6910

Please enter a valid zip code.

Please enter a valid zip code.

Aug 03 2023
Love0

How Do You Calculate The Number of Panels on a 16 kW Solar System?

By How Do Solar Panels Lower Your Electric Bill?, The Pros and Cons of Rooftop Solar in 2025 No Comments

There’s something exciting about putting a nice round number on the amount of solar panels you need. The number of kilowatts in a solar system doesn’t mean much to most people, but the number of panels on a roof paints a vivid picture.

16 kW is a rather large solar system, but entirely feasible for a household with high electricity consumption and an EV or two charging in the garage. And the more electricity you’re using at home, the more you can save by going solar.

So if you yourself find yourself looking for that sweet sixteen, here’s how to find out how many panels you need,  how much electricity you can expect them to produce, and a ballpark cost for the solar panels and installation.

How many panels are in a 16 kW system?

There are typically 40 solar panels in a 16 kW solar system with a power rating of 400 Watts each. However, this number can vary depending between 35 and 50 on the power rating of each panel.

To determine the number of panels in a 16 kW (kilowatt) solar system, we need to consider the wattage rating of the individual solar panels.  This “nameplate” rating signifies the maximum power the panel can produce in ideal conditions.

Assuming each solar panel has a wattage rating of 400 watts (by far the most popular power rating on the  solar.com marketplace), we can calculate the number of panels needed in a 16 kW (16,000 Watt) solar system as follows.

System size (Watts) / panel rating (Watts) = Number of panels

Using this equation, we find that it takes 40 solar panels with a rating of 400 Watts each to make up a 16 kW solar system.

 

Whether you are looking for a 16 kW system, or a 6 kW system you can apply the same method to determine the number of panels needed to meet your production needs.

 

 

How much electricity can a 16 kW solar system produce?

A 16 kW solar system can be expected to produce between 62-85 kWh per day in its first year, depending on how much sunlight it gets per day and energy lost during the conversion from DC to AC electricity.

In northern states like New York that average ~4 peak sun hours per day, a 16 kW system would produce closer to 62 kWh per day in its first year (assuming 2% conversion loss). In California and sunny southern states with closer to 5.5 peak sun hours per day, production should be slightly over 85 kWh per day.

Map showing the amount of sun hours in each region.

To put that in perspective, running an average central air conditioning unit running nonstop for 24 straight hours would consume around 80 kWh, so 66-90 kWh is quite a bit of electricity per day.

To calculate expected production, start by taking the system size (16 kW) and multiplying it by the average peak sun hours for your location (shown in the map above).

16 kW × 4 hours per day = 64 kWh per day

Then, subtract 2% of the total DC production to account for efficiency loss when converting to AC electricity that is used in your home.

64 kWh – 1.28 kWh = 62.72 kWh per day

It’s worth noting that solar panels slowly decline in performance over time through a natural process called degradation. Most modern panels come with performance warranties that guarantee that they will be able to produce 85-92% of their original nameplate output after 25 years.

So, your 16 kW solar panel system will produce slightly less energy each year, but it’s normal and can be accounted for.

How much does a 16 kW solar system cost?

A 16 kW solar system typically costs between $56,000 and $64,000 before incentives, depending on your location, installer, equipment, financing method, and complexity of the project. Claiming the 30% federal solar tax credit would reduce the net cost to between $39,000 and $45,000.

Is that a lot of money? Yes. But does that mean a 16 kW solar system is expensive? Not compared to grid electricity. In fact, larger solar systems typically deliver greater overall savings because they come at a lower Price Per Watt (PPW) and offset more utility electricity costs.

Let’s say you live in New York and you use, on average, 63 kWh of electricity per day. The chart below shows the cumulative cost of buying a 16 kW solar system to produce that electricity versus purchasing that electricity from a utility provider.

Graph showing the life time cost of a 16 kW solar system vs New York grid.

Over 20 years, we can expect a 16 kW system in New York to produce ~380,000 kWh of electricity. Purchasing that electricity from a utility at the state average rate would cost nearly $108,000, assuming average annual rate hikes of 3% per year.

Factoring in New York’s monthly net metering fee:

  • If you buy a 16 kW solar system with cash, you would pay around $46,000 for the 380,000 kWh of electricity
  • If you purchase a 16 kW solar system with a 20-year loan, your all-in cost is closer to $68,000 dollars with interest, but your monthly solar payments are less than your average utility bill on Day 1

Compared to $108,000 for grid electricity, $46,000-$68,000 for a 16 kW solar system doesn’t sound so bad… and we used pretty conservative pricing for this example.

Bottom Line

16 kW is considered a fairly large solar system. But when properly sized and installed, bigger solar systems typically provide more bang for your buck than smaller systems. 

The key to maximum bill savings and emissions reductions – for any size solar system – is to work with a reputable installer that will do the job right the first time and provide excellent customer service in the off-chance that issues arise.

Click here to compare quotes from solar.com’s network of reputable local installers.

 

Aug 01 2023
Love0

Electrum’s New NEM 3.0 Savings Calculations Show Path to Maximum Bill Reduction in California

By How Do Solar Batteries Work?, Solar Battery No Comments

In a breakthrough for California’s residential solar market, Electrum is now offering the industry’s most accurate NEM 3.0 savings calculations and, in doing so, illuminating a path for homeowners to use solar and battery storage to achieve the minimum monthly bill payments enjoyed under NEM 2.0.

Before NEM 3.0 solar billing took effect in April 2023, a solar system designed to produce 100% of a homeowner’s average electricity consumption could also be expected to offset ~100% of the homeowner’s electricity bill (aside from certain non-bypassable charges). But given the extremely low export rates of NEM 3.0, a solar-only system designed to produce 100% of a homeowner’s electricity usage only provides roughly 55% bill offset. This potentially leaves homeowners with solar payments and leftover utility bill payments to make each month.

Electrum’s calculations for two new battery discharge modes show a path 70-90% bill offset and a payback period between 5-7 years for solar and battery systems purchased with cash.

Discover your path to maximum NEM 3.0 savings. Start here.

Battery discharge modes: The key to maximum savings

The defining feature of NEM 3.0 solar billing is that solar export rates are ~75% lower than they were under NEM 2.0. Instead of earning retail value for the excess electricity their solar systems push onto the grid, solar owners typically earn somewhere around 4-5 cents per kilowatt-hour.

So, instead of exporting solar electricity to the grid for little-to-no value, it’s much more valuable to store and use it onsite to avoid drawing electricity from the grid – especially during peak pricing.

But the question is: When are the best times to charge, store, and discharge batteries under NEM 3.0?

With 576 different export rates that change by the hour, day, month, and year, the calculations required to answer this question are mind-boggling. Electrum’s tech team dug in, crunched the numbers, and built the only platform where homeowners can get a clear and accurate picture of their potential savings with three different battery discharging modes and compare multiple binding quotes all in one place.

The old calculation: Time-of-Use (TOU) mode

Electrum’s first, and most conservative, iteration of battery calculations was based on charging the battery with excess solar production and discharging it only during peak time-of-use hours. The idea is to avoid pulling electricity from the grid when it’s most expensive (summer evenings).

Under this discharge mode, a homeowner with an 8 kW system producing 9,500 kWh per year with a Tesla Powerwall 2 could expect to save $624 per year in avoided utility costs.

chart showing annual bill savings based on battery discharge modes under NEM 3.0 solar billing

The new calculations: Surplus and Optimized modes

Electrum’s calculations for two new battery discharge schemes show substantially greater bill reductions and savings than the time-of-use mode.

In the Surplus scheme, the battery is charged with excess solar production and discharged anytime household electricity usage is greater than the solar production. The big difference is that the TOU scheme is limited to discharge only during TOU hours. In Surplus mode, the battery can discharge at any time and further reduce importing and exporting from the grid.

Under the Surplus scheme, a homeowner with an 8 kW system producing 9,500 kWh per year with a Tesla Powerwall 2 could expect to save $1,103 per year in avoided utility costs – $32 per month more than the TOU scheme.

In the Optimized scheme, the battery is charged with excess solar production, but the battery uses a predictive model to discharge at the optimal times to prioritize savings. In other words, the battery learns the homeowner’s consumption habits and optimizes its charging/discharging schedule accordingly.

Using this mode, homeowners can take advantage of peak export windows in September, when utilities will pay several dollars per kWh of electricity exported onto the grid.

Under the Optimized scheme, a homeowner with an 8 kW system producing 9,500 kWh per year with a Tesla Powerwall 2 could expect to save $1,368 per year in avoided utility costs. That’s $62 more per month than the TOU scheme!

Optimized mode presents a real opportunity for homeowners to achieve 100% electricity bill offset and sets them up for Virtual Power Plant (VPP) programs forming in California.

 

 

Why are the new calculations a big deal?

For homeowners, Electrum’s new battery discharge calculations revive the once-lost hope of achieving:

  • 5-7 year payback periods that have come to be expected of California solar systems
  • Solar and battery payments lower than their average electricity bill (aka Day 1 savings)

The new calculations also present a promising new chapter after a rocky start to NEM 3.0.

Since it passed in April 2023, NEM 3.0 and its 576 export rates have posed a real challenge to the solar industry. Frankly, rooftop solar companies have struggled to accurately calculate and communicate savings potential to their customers.

While some companies offered overly conservative savings estimates that failed to attract customers, others knowingly over-promised savings and ignored the very real prospect of “leftover bills” to sell systems that are doomed to fall short of expectations. A third group shied away from the challenge altogether and reverted to selling leases and power purchase plans (PPAs) that are less beneficial to homeowners.

In addition to being exposed to desperate sales tactics, Californians are getting solar quotes that are all over the map and finding it difficult – and frustrating – to navigate the solar process.

Thanks to relentless work from Electrum’s technology team, homeowners now have a North Star to follow when navigating the California solar industry, and a platform to get accurate NEM 3.0 savings estimates based on binding quotes from trusted installers.

Explore your solar and battery savings potential here.