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Solar FAQ

Here is a list of the most frequently asked questions from our customers regarding solar basics and typical solar projects. If you don’t find what you are searching for please do not hesitate to give us a call to discuss your particular project at (650) 938-9574.

How Much Solar Do I Need?

The size of the solar power system required depends on individual criteria such as your annual electricity use, the amount of space for solar panels, and the percentage of your annual electric bill that you want to eliminate. Businesses typically try to eliminate as much of their annual electric bill as possible.

How Much Space is Required

Solar panels require approximately 80 to 100 square feet to produce 1 kilowatt or 1000 watts of AC Power. In some cases there is more room required for tilted panels to avoid inter-panel shading. For example, a 15,000 square foot flat roof can usually accommodate a 125-150KW or larger system solar power system depending on the mounting method.

Where Can the Solar Panels Be Installed?

Solar panels can be mounted virtually anywhere on your property if there is enough space. Roof-mounted systems are most commonly used, and there are several methods of attaching systems to your rooftop such as direct attach and ballasted (non-penetrating) systems.

Another popular method is ground-mounted systems, which also have several different configurations such as fixed-tilt ground mounts, single and double axis tracking, and carport canopy systems.

What is Required for Operation and Maintenance?

Modern grid-tied solar power systems generally require very little maintenance. Under normal conditions the only maintenance required is cleaning the solar panel surface once or twice per year depending on your environment. Systems can lose approximately 5% of their output if left soiled for a few years.

Solar power systems operate automatically and do not require any manual intervention unless there is a technical fault.

How Long Does the System Last?

Solar panels are solid-state electronics and have no moving parts. The silicon cells are encapsulated inside the panel and completely weatherproof. It is very rare that a “quality” solar panel will fail within 30 years. The quality of the panel construction will become evident in the 5th to 10th years of operation, which is why it is important to select panels built by a reputable solar company such as SunPower. If there is a failure in a panel, it’s nice to know that company as large as SunPower will still be in business and can provide replacements. Inverters have a typical life span of 15-20 years.

What Warranties are Included?

Cobalt Power includes a full 10-year warranty on all commercial solar power systems. In addition, all solar panels that we use have a 25-year manufacturer’s warranty, and all inverters come with a 10-year warranty.

How Much Does Solar Cost?

Solar system cost are generally based upon a $/DC Watt installed. Basic system budgets are around $3.50-$5.00 per watt AC. Don’t be fooled by the AC / DC “switcheroo.” If your estimate from a competitor looks much cheaper, make sure that you’re talking apples to apples.

There are rebates and tax incentives that will help lower the system price. The incentives are constantly changing, usually depleting, or being reduced. The cost of materials is slowly coming down, but not as fast as the incentives are. Now is the best time to buy.

How Long Before My Investment Pays For Itself?

The typical commercial system combined with the current rebates and tax incentives can usually pay for itself in about four to eight years. That is considering that the typical utility costs escalate about 5-6% per year which is approximately the number provided by the California Public Utilities Commission

What Permits Are Required to Build and Operate Solar?

As with all other construction, building permits are required for a solar power system. Usually an electrical and a structural permit is required and engineering needs to be included. Cobalt Power handles all of this for you as part of the package.

Once construction is completed, the system needs to be interconnected with the local utility company. There are applications and inspections required in order to complete this phase. Cobalt Power handles all of this as well. Once the system is interconnected, there are no other special permits required to operate the system.

How Do I Get Started?

Call Cobalt Power today to discuss the basics at (650) 938-9574. You can also compile twelve months of electric bill energy use and cost. If this is not available, we can guide you through acquiring the information online through your utility company’s website.

How Long Does It Take To Install?

Actual installation time depends on many factors, such as system size and system type. A typical 100KW system can take as little as six weeks for actual installation, while some more complicated systems can take up to twelve.

From the time you sign a contract until actual installation also depends upon many factors, like the complexity of the project design, the local jurisdiction’s permitting process, the CA rebate approval process, and, in some cases, the availability of materials. You can expect installation to begin within 2-3 months from the contract signing.

The overall time of completion depends upon many factors, but rest assured that Cobalt Power will deliver your system with speed and efficiency while still maintaining our extremely high standards of quality.

What Is Required Of Me During the Process?

Under normal circumstances the only thing required of customers during the entire process are to:

  1. Provide energy usage information for design
  2. Approve the system design
  3. Sign the contract, forms and applications required
  4. Have a company representative available to pay the progress payments as outlined in the contract
  5. Be available for the final walk through and completion sign-off

What is the Difference Between AC and DC System Size?

AC is Alternating Current and is the type of electricity that your building uses. DC is Direct Current and is similar to what your automobile and flashlights use. Solar panels produce DC electricity that has to be converted to AC. SOLAR SYSTEMS produce AC electricity so that your building can use it along with selling the excess back to the utility company.

Solar Panel Manufacturers produce panels with a laboratory “nameplate rating”. Under perfect conditions a 200 watt DC solar panel will produce 200 watts DC. Under normal operating conditions solar panels lose about 12% of their “nameplate rating”. This is the weighted efficiency rating of the panel as classified by the California Energy Commission.

Solar power systems convert DC to AC with the use of an “inverter” that acts as a power conditioner. In the process of conversion your system loses about 3-5% of the DC electricity generated by the solar panels to heat and efficiency losses. Because the conversion is required in all cases the important numbers to compare are the AC Output Ratings of the entire system (commonly referred to as the CEC Rating). The conversion, along with the real world DC output of the panels usually account for a system rating that is about 85% of the total nameplate rating (ie 118KW DC is really a 100KW AC system).

Solar installers use a variety of methods for describing the size of the solar power system that they are quoting. There are some that purposefully attempt to misinform customers by giving estimates with DC cost per watt only. This make the system either appear cheaper or larger, either way as a better value. Since you cannot use a DC powered system to power your building Cobalt Power quotes all systems with both the AC and DC system sizes shown clearly.

What is Net Metering?

The owner of a grid-connected PV system can often sell as well as buy electricity each month! This is because electricity generated by the PV system can be used on site or fed through a meter into the utility grid. When a home or business requires more electricity than the PV array is generating (for example, in the evening), the need is automatically met by utility power. When that home or business requires less electricity than the PV array is generating, the excess can often be fed (or sold) back to the utility through net metering, which is becoming more and more common throughout the nation.

What is the Energy Payback Time?

The EPT is the time it takes a PV system to generate enough zero-emissions energy to equal the energy used to produce it. Solar power systems have a very low EPT or Energy Payback Time of approximately 1.5 years.

Should I Wait for Solar to get Cheaper Before I Buy?

The simple answer is no. The incentives available today will not last forever. The CSI rebate is on a scheduled reduction based upon the number of projects that get installed. A few years ago it was about $4.50 per watt installed. Now it is approximately a $1 per watt.

The Federal Investment Tax Credit (30%) only lasts until the end of 2016. It was only a temporary measure that was included in the American Recovery and Reinvestment Act of 2009. At that point, it will be up to the Congress to decide if they want to extend this credit into the future. Given the enormous benefit of having 30% of your system paid for by the Federal Government, it makes sense to act now and not to wait.

The bottom line is that incentives are here to make the cost of going solar close to grid parity which is very close with incentives. The decline in incentive levels were originally designed to follow the decline in equipment and system costs. Generally over the last 8 years incentives have declined faster than installed costs… so no, it’s not getting any cheaper.

What Permits are Required to Build and Operate Solar?

As with all other construction, building permits are required to construct a solar power system. Usually an electrical and a structural permit is required and engineering needs to be included. Cobalt Power handles all of this for you as part of the package.

Once construction is completed, the system needs to be interconnected with the local utility company. There are applications and inspections required in order to complete this phase. Cobalt Power handles all of this as part of the package as well.

Once the system is interconnected there are no other special permits required to operate the system.

Note on Contractors Licenses


Unlicensed illegal contracting is an offense that is punishable by fines and prison time. You may not have any legal recourse if your unlicensed contractor installs your system incorrectly. You have less legal power if you hire an unlicensed contractor and they disappear with your deposit. Please hire responsibly and check out your contractor on the Ca State Contractor Board website.

If a solar “retailer” gives you a bid for a turn-key solar power system that does not clearly state the installation contractors name and license number they are breaking the law. All forms of bids or advertisement (including proposals, fliers or business cards) for any property improvements must clearly state the contractor’s license number on them. The only types of contractors licenses allowed to perform solar projects are A-Engineering, B-General, C10-Electrical, or C46-Solar.

Why install a PV (photovoltaic) system?

PV systems can be a great investment, generally yielding 15-30% per year Return on Investment (ROI), tax-free.  Modern PV systems are safe, quiet and reliable, and are close to maintenance-free.  They provide a measure of energy independence, and they help the environment.  Besides, they are cool!  The sight of your utility meter running backwards is great!

Can a PV system actually pay for itself?

Yes, a PV system can not only pay for itself through the energy cost savings, but if you finance the system with a home equity line, in many cases it can generate immediate positive cash flow.  That is, your monthly energy cost savings can be greater than your monthly loan amount from day one.  Current government-sponsored rebates and tax credits can pay for 35-50% of your installed system cost. When this is combined with Time of Use (TOU) metering, PV systems are extremely attractive from a financial standpoint.

Is this the right time to install a PV system?

Electricity rates have gone up an average of 5.4% per year for the last 39 years, and this trend is likely to continue.  Excellent rebates are currently available, but these are declining rapidly.  Yes, this is a great time to install a PV system.

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