HVAC Retrofit

10kw Solar Array

Office Efficiency

Array output (per day):

October: 482.8 KwH (15.6)

November: 344.8 KwH (11.5)

December: 162.0 KwH (5.2)

January: 305 KwH (10.6)

February: 454 KwH (15.7)

March: 645 KwH (20.8)

April: 896 KwH (29.9)

Lifetime: 3572 KwH as of 05/01

JBDG's Solar Array

-operational since Sept. 15 2007-

Companies like to say they are working to help the environment by buying credits to offset carbon emissions. This is a great goal, but it's far from ideal to help ensure a 'green' corporation. We're taking a much larger step forward to lessen our impact on the environment.

In late July 2007, JBDG, Inc began undertaking a precedent-setting project for small business owners in the Northwest; the installation of a 10kW photovoltaic array. This project covers a large amount of the electrical use of our facility - depending on time of year, between 350 to 2000 kWh monthly. Even better, once all of the rebates and tax incentives are factored in, the project will pay for itself in approximately 10 years. Not bad, considering the panels have a 30-year lifetime.

• A photo gallery of the array installation and site prep is available.
  
  Frequently Asked Questions:
  "Exactly how much energy will a 10kw solar array in Seattle generate?"
  

The answer is fairly simple: just over 10 megawatt hours annually (or 10,000 kWh). That's the equivalent of consuming 1154 watts constantly for a year or to put it another way, equal to the output a typical nuclear power plant generates every 30 seconds.

As we gather data monthly from our inverters, we will be updating out array output numbers along the bar on the left. As you can clearly see, as summertime months near here in Seattle, our daily output is dramatically climbing. We already have enough output to more than cover the average household's consumption in the United States. The array is performing exactly as we have predicted.

"How long can you operate without grid-power?"

We have 8 extremely large and heavy batteries that'll give us a total of 2300 amp hours of backup electricity. Each battery weighs 200 pounds, so that's literally, nearly ton of batteries. We're operating two separate, redundant solar arrays and inverters side-by-side. Each are capable of 5kw of AC electricity. One system runs our workstations, while the other is dedicated to the servers and building systems. If you look at those numbers, without using the panels to charge the batteries, we can run one of our workstations 770 hours before draining the batteries dry. In case you were wondering how that math works: 1160 amp hours, divided by 1.5 amp hour consumption of a computer (200 watt consumption), equals out to 32 days of electricity.

We don't backup the entire office on our batteries. Only a dozen workstations, duct fans, and our servers are tied directly into the battery backup system. We can also charge a large number of laptops. With the solar panels charging during the day, we can operate indefinitely, year round and keep the building heated in during any extreme weather condition. Quite the benefit for our locally unstable electrical grid.

"What equipment do you use?"

"Will solar ever pay off for you?"

The simple reply is, YES! The total installed cost of the system is $96,797. That's a little on the high side, since with went with such a large battery backup. Since this is a commercial install, JBDG, Inc. is eligible for an instant 30% federal tax credit worth $29,039. Accelerated depreciation over 5 years will also cut $21,722 out of the cost of the system. Factor in the Washington State Production Credit, $13,579, and the value of the electricity not used, $14,074 over eight years. That totals to be over $75,000 return on investment within the first 8 years (ROI of 80%). This doesn't take into account the value increase of the property. We estimate a 10 year return on investment. The system's panels are warranted to last until 2032. By that time, we will have saved $31,505 in electricity. That's the number we'd come to using 2007's energy rates. Taking into account historically rising energy costs, over three decades, we can expect our rates to triple. That would easily double our saved electrical costs to above $60,000.

We hope this system will set an example for other businesses, proving that solar power makes sense even in a city as far North as Seattle. We hope they will follow our lead and help ensure America's energy independence.

© Johnson Braund Design Group, Inc.