Tuesday, June 28, 2016

SolarEdge DC Optimized Inverters and Telsea

SolarEdge will be supplying an inverter system that will enable photovoltaic (PV) and grid integration with Tesla’s recently announced Powerwall home battery – a storage pack capable of supplying electricity for homes when the sun goes down. Combining their technologies, the partners said they are building upon SolarEdge’s DC-optimized inverter solution and Tesla’s automotive-grade energy-storage technology to provide a more economical solution for residential solar generation.

“Tesla’s collaboration with SolarEdge unites leading organizations in two rapidly growing industries, solar energy and energy storage, to bring homeowners a more cost-effective and integrated energy generation, storage and consumption solution,” Tesla CTO J.B. Straubel said. “SolarEdge’s commitment to improving the value of PV systems through product innovation, combined with more than 1.3 gigawatts of successful deployments, makes it an ideal partner for Tesla to develop and introduce this new energy-storage solution to the PV market.”

Tesla, which has dazzled the electric-car market with its fastcharge car batteries, announced its new wall-mounted rechargeable battery last week.

The Powerwall will be available in a 7-kilowatt-hours daily cycle version for everyday use and for backup in the event of a power failure or disaster. This inverter system is priced at $3,500.

The battery is designed to collect solar energy accumulated daytime hours and use it to power the home in the evening and morning, when electricity usage is highest but sunlight is lacking.

“We have this handy fusion reactor in the sky called the sun. You don’t have to do anything – it just works. It shows up everyday and produces ridiculous amounts of power,” Tesla CEO Elon Musk said at last week’s launch event for Powerwall, which was fully powered by solar-charged batteries.

The batteries could potentially provide a sort of “smart grid” solution without actually needing a smart grid, according to Tesla. Although they are marketed as a solution for storing solar power, the batteries can also store electricity from the grid during less-expensive offpeak hours and then supply it to the home during the expensive peak hours when there is highest demand.

Monday, December 21, 2015

In key solar decision, California rejects utility plans

The California Public Utilities Commission delivered a major win for rooftop solar and a serious blow to the utility industry Tuesday, proposing to leave mostly in place a program that encourages homes and businesses to go solar.

Southern California Edison and other utilities lobbied the commission to slash the rates at which solar customers are paid for the electricity they generate, and to approve new monthly charges. Under Edison's proposal, the average solar customer would have seen her or his monthly bill increase from $65 to $135 — a difference of more than $800 per year.

Clean energy advocates feared the commission would back the utility industries' proposals, as it has in the past. But Commission President Michael Picker didn't give the utilities what they wanted, rejecting new monthly fees and demand charges. Solar customers would continue to be paid for their excess generation at full retail rates under his proposed decision.

“Gov. Brown’s (utilities commission) is standing up for clean power and for customers by proposing to reject the utilities’ attempts to make solar out of reach for customers,” Bernadette Del Chiaro, executive director of the California Solar Energy Industries Association, said in a statement.

Thursday, October 8, 2015

Solar Sizing and Payback

How To Determine The Right Size Solar System For You

Many people call into the office and immediately want to know what a solar system will cost them for a 2000 sq ft home. The answer is it depends on the following:

1. How much is your last 12 months usage in kilowatt hours (KWH) on a monthly basis? This information can be plugged into a solar sizing software program and give you a very good idea as to the sizing and pricing of your new solar system.

2. What electric rate are you on? Some rates are cheaper than others and the price you pay for your electricity will affect the size and price of your solar system.

3. What Energy Savings can you incorporate now and down the road? This information is very useful due to the fact that future energy savings should be evaluated into the size of your currently planned solar system.

4. Are you comfortable? Many people are cutting back so as not to get hit with the seasonally high bills air conditioning creates. With all of the cash, tax advantages, and exchange rate subsidies, adding more energy production now is very inexpensive.

5. How well can you take advantage of the Time of Use TOU exchange rate when incorporated into solar?

6. How efficient of equipment are you willing to invest in? We will get into efficiency of solar panels and inverters at a later date. But the bottom line still exists, more efficient equipment produce more energy and usually degrade (lose efficiency) at a slower rate, and can also carry better warranties. Quality and efficiency affect pricing.

7. What if any solar shading issues need to be addressed as well as what direction and angle the solar panels will be facing.

As you can see, if just one or two of the above mentioned items are not addressed, you could be substantially off on what size of system you need and what your overall expense is going to be. This is not all that difficult for a knowledgeable industry professional. However, many salespeople just want to sell customers a larger system to make a larger commission or are instructed to under size systems to make the rate of return on investment as well as the number of years for the system to pay back look best.

At Nova West Solar, we are committed to helping educate consumers on solar as well as system sizing. Proper system sizing, coupled with high efficiency German equipment and competitive pricing makes Nova West Solar the right choice.

Sunday, December 8, 2013

Solar Panel Payments Set Off a Fairness Debate


In California’s sun-scorched Central Valley, the monthly electric bill can easily top $200. But that’s just about what George Burman spent on electricity for all of last year.
Ann Johansson for The New York Times
Solar panels generating energy for a condominium complex sit atop a parking garage roof in Santa Monica, Calif.
When the sun is shining, the solar panels on his Fresno condominium produce more than enough power for his needs, and the local utility is required to buy the excess power from him at full retail prices. Those credits mostly offset his purchases from the electric company during cloudy days and at night.
Mr. Burman says the credit system, known as net metering, is a “very nice benefit” for him. But it’s not such a good deal for his utility, Pacific Gas and Electric.
As he and tens of thousands of other residential and commercial customers switch to solar in California, the utilities not only lose valuable customers that help support the costs of the power grid but also have to pay them for the power they generate. Ultimately, the utilities say, the combination will lead to higher rate increases for everyone left on the traditional electric system.
“Low-income customers can’t put on solar panels — let’s be blunt,” said David K. Owens, executive vice president of the Edison Electric Institute, which represents utilities. “So why should a low-income customer have their rates go up for the benefit of someone who puts on a solar panel and wants to be credited the retail rate?”
The net metering benefit, which is available to residential and commercial customers with renewable energy systems in more than 40 states and has helped spur a boom in solar installations, is at the heart of a battle. Utilities, consumer advocates and renewable energy developers across the country are fighting over how much financial help to give to solar power and, to a lesser extent, other technologies. Regulators are in the middle, weighing the societal benefits of renewables as well as how best to spread the costs.
Net metering has been so popular that several states are rapidly approaching regulatory limits on how many systems are eligible, meaning new customers have no assurance they can reap the same rewards. The solar industry, which is growing in size and influence, has been pressing to raise those limits to continue to encourage rooftop installations, while the utilities have generally been opposed.
In a closely watched decision that could influence the path of other states, California regulators decided last month to effectively double the amount of solar power capacity eligible for net metering. More than 60,000 people wrote to the Public Utilities Commission in support of raising the cap, which would allow new customers to continue being credited at a high rate for electricity they produce but do not use.
But representatives of the three major utilities that are covered by the decision said it would simply shift the fixed costs of maintaining the electric grid, which are embedded in electric rates, to other customers.
Other states, including New York, Massachusetts, Louisiana and Virginia, have also been reviewing their programs, which are transforming the fundamental relationship between customers and their utilities.
In Massachusetts, which pays net metering customers close to the retail electricity rate, lawmakers recently revised the tariff program to create separate caps for the public and private sectors. The Department of Public Utilities is currently seeking to clarify which entities, like schools and universities, should count against each cap, an issue of some urgency since the private limit is close to being reached.
Some states have also begun to impose new fees as they have increased the amount of power customers are allowed to generate and sell. When Virginia doubled the size of home systems eligible for net metering to 20 kilowatts last year, it allowed the main utility to start charging a monthly fee this year for owners with systems larger than 10 kilowatts.
The policy choices could have profound and lasting effects. The federal Department of Energy envisions a future in which a typical homeowner might feed power into the system from solar panels, small wind turbines or electric vehicles sitting idle in the garage, offsetting charges for power used at a later time and helping provide energy to the system during periods of high demand. Steven Chalk, the deputy assistant secretary for renewable energy, said that net metering was critical to realizing that future, “where users are very involved in what they’re using in terms of demand and what they’re also generating.”

Saturday, December 7, 2013


Electric Cars and Solar Power

We have a lot of customers that are looking to install solar on their homes and are also considering an electric car. We call this our Electric Car Option. Although we can’t help you get your new Tesla any faster due to the long lead times, we can help you generate the power so you won’t ever have to go to a gas station again.

Here’s how it works. From Wikipedia, I pulled the following information.

The Roadster is the first production automobile to use lithium-ion battery cells and the first production EV to travel more than 200 miles (320 km) per charge.

The world distance record of 501 km (311 mi) for a production electric car on a single charge was set by a Roadster on October 27th, 2009 during the Global Green Challenge in outback Australia.
According to an independent analysis from the U.S. EPA, the Roadster can travel 244 miles (393 km) on a single charge of its lithium-ion battery pack, and can accelerate from 0–60 mph (0–97 km/h) in 3.7 seconds. The Roadster’s efficiency, as of September 2008, was reported as 120 mpgge (2.0 L/100 km). It uses 135 W·h/km (21.7 kW·h/100mi or 490 kJ/km) battery-to-wheel, and has an efficiency of 92% on average.

So, let’s believe the EPA for a moment and assume that the Tesla can indeed go 244 miles on a single charge. How much electricity does a single charge require? Well, we go back to Wikipedia for an answer.

A full recharge of the battery system requires 3½ hours using the High Power Connector which supplies 70 amp, 240 volt electricity; in practice, recharge cycles usually start from a partially charged state and require less time. A fully charged ESS stores approximately 53 kWh of electrical energy at a nominal 375 volts and weighs 992 lb (450 kg).

A little math shows that 70 Amps x 240 Volts = 16,800 Watts or 16.8 kWatts. If we charge the car for a full 3 1/2 hours, we get 16.8 kWatts x 3.5 hours = 58.80 kWatthours.

Thus and Therefore, if we charge the car with 58.80 kWhs and we can go 244 miles then we get the result that the car requires 0.24 kWhs per mile.If you drive 30 miles per day, we can then assume that 30 miles/day x 0.24 kWhs/mile = 7.23 kWhs/day to run your car.

Well, how many solar panels are required to generate 7.23 kWhs/day. In general, a good rule of thumb is that one module will generate 1 kWh per day, on average, over the course of a year.
Approximately 8 solar modules will power your car 30 miles per day!!!

All this math adds up to one thing. It is and will become incredibly cost effective to power your car with solar panels. Right now, with State and Federal rebates cutting the cost of solar by about 40%, it is similar to having the government pay for half of your gas bill.
When thinking about putting solar on your home, consider the electric car option.

How to Shoot Down Your Energy Bill

Author Gary Fairhead
Nova West Solar Inc.

In the typical house 38% of all lost heat escapes though leaks and cracks in the shell of the building. That's a lot of heat and money gone with the wind. A particularly drafty house might have the air completely replaced up to 10 times every hour. Ideally the air should only refresh once every hour or two.

Though it can be difficult to find all nooks and crannies where heat is on the way out, hunting them down and plugging them up can be the most cost-efficient way to lower your energy bills. Extra bonus: any steps you take to make your house warmer in winter will also serve to make it cooler in the summer by keeping heat out.


You have to be a bit of detective to seek out all the chinks where drafty air is slipping in. Experts recommend using a couple of lit incense sticks for this. Simply close all your doors and windows on a fairly windy day then light your incense. Take a tour of the house, holding your incense near potentially leaky spots to see if a draft is present. You can also pay to have a "blower door" test performed by a contractor.

Some of the more common entry and exit points to look for:

- Around doors and windows

- Cracks in walls (interior and exterior)

- Attic and basement doors

- Chimney damper

- Seal between roofing and chimney

- Seal between siding and eaves

- Spaces around wall switches and outlets

- Spaces around outside taps and any plumbing the penetrates the exterior walls

- Seal between the foundation and sill

- Any place where cables, phone lines or wiring enters house

- Any place that ducting or vents penetrate the walls

The good news is that increasing your home's energy efficiency by sealing up these energy sucking gaps is the cheapest and single most effective way to save money on your heating bill. Most repairs can be done with weather-stripping and caulking which are both inexpensive.


A caulking gun will take care of all the most conspicuous leaks like those around windows and doors. Make sure to plug up any holes that let cables into the house, any space around taps for the garden, and the often overlooked seals between the house and the roof and foundation. For really large gaps, staple plastic sheets over the space or stuff them with strips of insulation, wood, rubber, sponge or heavy rope first, then seal with caulking. Caulking materials are flexible, paint able and should last up to twenty years.

TIP: Aerosol foam can also be used to seal large gaps like those that can be found at the foundation.


WINDOWS: Windows that open and close will also need weather-stripping around the sash. Metal stripping is a good choice that lasts a long time and can be used in conjunction with other types of stripping to get a good seal. Vinyl or foam rubber gaskets are also popular easy to work. Felt or foam rubber strips should be attached along edge of the sash that meets with the frame to create a tight seal when window is closed.

TIP: Hanging heavy drapery that blocks the chill is another way to reduce heat loss through your windows.

DOORS: Doors will need weather-stripping around the top and sides as well as a good seal at the bottom. Cheap felt or foam rubber strips work well around door jams to create a snug fit when door is closed. Vinyl or foam rubber gaskets or interlocking jam strips can also be used here. Drafts can be kept from sneaking under doors with an easily installed door sweep or door shoe. You'll probably have to take your doors off their hinges to do this job properly.

TIP: In addition to weather-stripping all doors that lead outside, be sure to seal any doors leading to unheated or rarely heated spaces like the garage, attic and basement.


CHIMNEY: make sure damper is closed tightly when you're not using the fireplace. If smoke can get out, so can warm air! Also check that the flashing is doing its job.

OUTLETS & SWITCHES: seal these with special insulating inserts that block air flow.

LIGHT FIXTURES: check for leaks and caulk or otherwise seal.

Saturday, May 4, 2013

How Utility Rates and Time of Use "TOU" Rates Work With Solar

Understanding Time of Use Rates
Gary Fairhead 2010

PG&E customers are billed according to “how much” electricity they consume. This volume of energy is measured in kilowatt hours i.e. kWh. “Tiers” have been created to “Price” the energy you use each month. These “Tiers” of energy increase in price as consumers consumption of energy increases. The first tier is what PG&E believes the average consumer “should” use to power their home. If consumers decide to use more than this “baseline” of energy, PG&E then starts increasing their pricing as consumption increases.

The following is a brief graph of how PG&E bills most customers. This is based on an E-1 electric rate in territory R B. Total electricity used it this example is 2255 KWH and the total cost is $723.05.

Tier 1 543 KWH $.11887 $62.61

Tier 2 162 KWH $.13502 $21.35

Tier 3 380 KWH $.28562 $98.70

Tier 4 569 KWH $.42482 $241.72

Tier 5 600 KWH $.49778 $298.67 (unlimited)2010 Pricing

As the above chart shows, the more energy you consume, the more PG&E charges you per KWH. Notice that the first two inexpensive tiers account for only $84 of your entire electric bill. From that point on you jump immediately from $.13 to $.28 per kwh and then on to $.42 and $.50 per kwh! After the first $84 per month, you will be paying a very high price for your electricity.

To help consumers go solar, there are financial incentives available for them including State rebates and Federal Tax Credits.

However, the one financial tool that is seldom given the credit it deserves is the “Time Of Use” rate i.e.TOU. Electrical current produced by a solar system is first used to satisfy the home’s electric needs. Should extra energy be produced, it is sent out to the grid to “help out” the community’s energy needs. California uses “Time of Use” rate structures for solar customers, which means that this excess electricity sent out to the grid during the day puts credits in the customer’s account at a higher dollar value than the electricity he buys back at night.

Summer TOU rate schedules

Summer Peak Pricing 1PM-7PM $.30 per kWh
Summer Part Peak Pricing 7PM-9PM 9AM-1PM $.14 per kWh
Summer Off Peak Pricing 9PM-9AM $.10 per kWh

During Peak hours, you account can receive a credit of $.30 per kWh for every kWh you send out on the grid! In addition to this, you will only be charged $.14 per kWh during Part Peak times and just $.10 per kWh in Off Peak times.

Because this “exchange” rate is so financially attractive, solar customers can utilize several tips to maximize their energy savings while increasing their kWh of consumption!

One tip is to over cool your home in summer months several degrees lower than you would like up to 1 PM. This is because you are now doing the major cooling of your home at the 11-14 cents per kilowatt hour rate. As soon as 1 PM arrives, you can have your thermostat automatically set back to the temperature you would normally set it at. Turn on some ceiling fans and now coast until the temperature forces the AC system to start cooling down your home. This “coasting” time should create 4-5 hours of high solar credits to your account to now use back at very inexpensive rates.

Pools and spa equipment, exterior lighting, laundry, and air conditioning utilized during Part Peak and Off Peak times are now billed at these very low rates.

Time of Use Rates can easily become a 2nd rebate that is usable for the entire life of the solar system. Without this exchange rate, customers would need to build a 20-30% larger solar system!

Conservation should also be utilized to increase your life style while lowering your energy demands. You will see many articles on energy conservation in our blog with more coming soon!