Solar Credits and STCs

First of all, you get ‘Solar credits’ for installing eligible solar systems in Australia. The credits are simply multipliers for renewable-energy incentives called STCs (or Small-scale Technology Certificates). What the heck is that? Well, it’s probably like a coupon or a gift certificate that you can redeem for cash (or tax credits), right? Wrong. They’re more like green energy stocks that are traded among registered agents or on a specific market called the ‘Clearing House’. What the heck is a registered agent? Maybe your installer. But maybe not.

When you install solar, you can apply to create the STCs and then sell them to an agent or sell them on the Clearing House. The standard price is supposed to be $40, but apparently the price fluctuates and is pretty much always less than that. So what are they worth? Basically they’re worth whatever somebody else will pay for them. Well, who’s going to pay for them? Registered agents. Well how do I find an agent to sell STCs to them? Search for a market like this one.

So, what to do about STCs? – Though some people like to keep them and trade them (like stocks?), many people ‘sign them over’ to the installer for a discount on the installation cost. You can’t sign STCs over until the system is complete, so at least wait until the installer has completely installed the system before you sign anything saying that the STCs are theirs. (*Tip: shop around for solar installers to see who will give you the best deal.)


Feed-in-tariffs

Next, we have feed-in-tariffs (FITs) which are premium rates paid for energy created by grid-connected renewable energy systems like rooftop solar panels and wind turbines. But the FITs vary depending on the State so check your local feed-in-tariff to see how much you can save.

For example a homeowner in Queensland with a rooftop solar pv system will earn 44 cents per kilowatt hour (kWh) for surplus electricity fed into the grid which is almost double the general domestic use rate of 22.76c/kWh as of 1 July 2011. (source)

But a homeowner in Victoria with the same system will only earn 25 cents per kilowatt hour for surplus energy. That’s just slightly more than the regular rate. (source)

Lastly, your energy retailer might offer a different feed-in-tariff rate from the minimum dictated by your state. It might be higher, but it can’t be lower. Shopping around for the best rate from electricity retailers is an option, but compare carefully. A higher FIT might mean you lose something else, so make sure you understand the contract before switching.

Summary

Going solar in Australia is a great idea, but the government(s) can do a lot better to simplify the process for the average consumer. Contact your local representative and ask for a simplified solar feed-in-tariff across the country (or sign the petition at FeedInTarrif.com.au). With all the sunshine Australia’s blessed with, the country should be leading in the way in solar!

Click here to have local Aussie installers contact you with free solar quotes.

1. Massachusetts – 4 years
2. Hawaii – 5 years
T-3. New Jersey – 7 years
T-3. Maryland – 7 years
T-3. Louisiana – 7 years
6. New York – 8 years
T-7. California – 9 years
T-7. Ohio – 9 years
T-7. Delaware – 9 years
10. Arizona – 10 years

If you want to know how much solar it could cost to go solar in your state? Check out the infographic below from 1BOG.org to see the average cost to go solar in your state. Then check out how much you can save each month, over 20 years, and the average payback time for solar.

Home Solar Power Discounts – One Block Off the Grid

1.  All solar panels are warrantied for 20-25 years, which means the manufacturer guarantees the panels will still be producing at least 80% output 25 years from now. It’s the same for all brands. Don’t believe me? Ask the guy selling them.

2.  It’s all electricity from the Sun. That’s it. Electricity is electricity. One brand won’t give you better ‘quality’ electricity than the next. All solar electricity is a step up from electricity from fossil fuels, which is dirty electricity, right? But some panels give you more electricity than the next. Of course, but…

3.  Don’t confuse efficiency with output. Efficiency is just that: how much it produces per area. If your roof space (or ground space) is limited, then, sure efficiency is important. But you don’t have to worry about it. Your installer will only offer you panels that fit in your installation area (ie roof). So, they’ll pick the ones as efficient as they need to be. But you want the ‘best’ or ‘most efficient’? Okay, but your bragging rights will cost you $1,000′s more and only last until the newest ‘most efficient’ panels beat yours by 0.01%.

So if panels don’t matter, what does?

Installing solar matters! You getting your electricity from the Sun, as opposed to a non-renewable energy source, is the best thing you can do for the future of humanity right now. We need energy. It’s the currency of our progress as humans. But that stuff in the ground is going to run out a few billion years before that thing in the sky.

Money matters. Not to you? Fine, not to me either, so how about time? Well time is money. So don’t waste either. Get the solar pv system with the best value!

Value matters. It’s as simple as: Total Cost ($) ÷ First year output (kWh). Good value (lower cost per output) means you’re getting the most bang for your buck (literally, the most electricity for your money).

If you really want to know, here are the 5 questions to ask solar installers. But, really there are only two questions you need to ask:

1. “How many kilowatt-hours will the system produce the first year?”

2. “How much does it cost (parts, labor, rebates – everything)?”

That’s it. Nothing about the solar panels. Nothing about brand, efficiency, or where the panels were made. Just get the system with the best value. Want to calculate value? Let me help: Simple Solar Value Calculator.

Wanna know how to choose the best solar panels? It’s simple: find out which ones give you the most electricity for the cheapest price. Let’s call this ‘solar value’.

Well, how do you figure out which panels give you the most electricity? Do I need to know which panels are the ‘most efficient’? Nope. Efficiency is not the same as output. Efficiency is output per area. You should only care about output. Let your installer worry about the area.

Okay, so how do I calculate output? Good news: you don’t have to. Your installer will do it for you. So, call a bunch of solar installers and let them do the work. Once you have 3 quotes, come back here to compare by calculating the ‘solar value’ for each quote.

Solar Value = Total Cost ($) ÷ First year output (kWh)

If you’re not sure, ask your installer these two questions, then you can see who’s give you the best deal:

1. “How many kilowatt-hours will the system produce the first year?”

2. “How much does it cost (parts, labor, rebates – everything)?”

1. Get your quotes ready
2. Visit the CSI online calculator
3. Plug in the data
4. Calculate!

Step 1: Grab your solar quotes and look for the specific solar module name and how many solar modules will be installed. Make sure you know the exact panel. Circle the panels and how many. Ex. 20 x SunPower SPR-200-BLK-U.

Then find the exact solar inverter in the estimate. This might be SMA SunnyBoy, Xantrax, Fronius, or Enphase. Circle this too. Ex. SMA SB4000US (240V).

Lastly, find the part that says ‘First Year Expected Output’ or ‘Annual output estimate’. Circle this. Ex. 4,800 kWh/yr.

Step 2: Use the CSI EPBB solar calculator to double check your installer’s solar quotes. This is the same calculator California installers must use to calculate official numbers used in the rebate paperwork. It’s okay if you’re not from CA, see below.

CSI EPBB Calculator

Step 3: Plug in the numbers from above.

Don’t live in California? No problem, you can still get a rough idea, or at least numbers to compare. Use Zip Code: 94109, Utility: PG&E, and everything is else the same.

Step 4: Calculate and compare. Scroll all the way to the bottom and look for the part that says “Annual kWh” and the number across from it. This is how much actual electricity you can expect from your complete solar energy system in the first year. It’s measured in kWh (kilowatt-hours), the same as your electricity bill!

The two most popular are SunPower and Sharp. Then, there’s a big drop off to Kyocera and Suntech. You won’t see BP’s number get any higher as the company has decided to shut down it’s solar division.

So, now that we know which solar panel brands are being installed the most, let’s see how difficult it can be to compare solar panels.

Solar Efficiency Basics → Tiers → Compare → Most Efficient → Table

Solar panel efficiency is simple, but there a few things you need to understand.

There are 3 main types of solar efficiency.

1.  Module Efficiency
2.  Area Efficiency (Density)
3.  Cell Efficiency

1.  Module efficiency measures how well a solar module (aka panel) converts the Sun’s energy into usable energy. If the Sun dumps 100 Watts of energy onto the module and the module spits out 15 Watts, the the module is said to have 15% module efficiency (15 W / 100 W = 0.15 = 15%). If you want to brag to your friends that you have a top tier efficiency panel, care about this.

2.  Area efficiency (aka Density) measures how much usable energy a module produces in a given area. It’s Watts per square foot, so the more Watts, the more energy you’ll get from a specific area (or available space on your roof). So if a module spits out 210 Watts in 15 square feet, it’s density is… c’mon, it’s Watts per square feet (and I made it an easy number). Okay, it’s 14 W/sqft (= 210 W / 15 sqft). If you have limited roof space, get the panel with the highest density.

3. Cell efficiency is measured the same way as module efficiency, but only with a single cell. This is the number news media and blogs love to tout in their headlines as ‘record breaking’ and ‘highest efficiency achieved’. This number is generally not useful for the average consumer. If you work in a solar cell lab, don’t give up on increasing this number.

So that’s the basics of solar efficiency. Now, let’s make it even simpler by dividing solar panels into 5 Efficiency Tiers (or levels).

Solar Efficiency Basics → Tiers → Compare → Most Efficient → Table

To simplify solar efficiency further, we have divided all modules into 5 tiers based on their efficiency compared to all other solar panels. Now installers and consumers can easily communicate about module efficiency.

Are the solar panels in the most efficient tier (Tier 1) or do they have average efficiency (Tier 3)? If modules are in the least efficient tier (Tier 5), let’s hope they’re cheaper than the modules in the above-average tier (Tier 2).

You no longer have to worry about the 4-digit efficiency value and wonder what it means. Is 13.81% efficiency good, bad, or average? Now, you can simply consider the Tier ranking of the solar module. A 13.81% efficiency is Tier 3, so it’s average efficiency! That simply means it’s in the middle 20% of efficiency (40 -59%) compared to all eligible modules.

Tier 1 Efficiency modules are in the top 20% of efficiency of over 7,300 modules eligible for California solar incentives. They are more efficient than 80% of the other solar modules. Basically, the smart ones in the efficiency class.

Tier 2 modules are more efficient than 60% of all other modules, while Tier 3 have basically average efficiency. Tier 4 is below average and Tier 5 modules are in the bottom 20% in terms of module efficiency.

How efficient are your solar panels?

“Below average, but I got a good deal on them.”

“The most efficient, because my roof space is limited.”

“My panels have average efficiency and my installer did a great job!”

There are three points I want to make.

1. Use the solar panel’s warranty to compare output loss over time because that is the only output you are guaranteed.
2. Realistically expect less than a 3% decrease in output the first year, and about .5% decrease per year after that for most panels.
3. One solar panel from 1979 was tested in 2010 (after 30 years) and its output was better than the original factory specs.

First, the industry standard for solar output warranties is 90% output in year 10, and 80% output in year 25. This is the 2011 warranty for companies such as JA Solar, First Solar, Yingli Solar, Canadian Solar, Sanyo, and Sharp. Right now there is not enough data to know reliable degradation rates after 20-25 years, so you must rely on manufacturer warranties in order to compare expected solar output losses over time.

Now, most solar panels won’t degrade this much. This is just want the manufacturers will guarantee. So, some manufacturers are starting to update their warranties to set themselves apart from the competition. Here is a list of the best warranties available from major solar panel manufacturers.

1. SolarWorld and Trina Solar both offer linear performance guarantees which basically means that they are guaranteeing only the small decrease for each year up to 25 years. Technically, it protects you a little more. Check both of their websites to see how they explain it.
2. Suntech protects you at year 5, 12, 18, and 25, which gives you more protection than the standard.
3. Sunpower warranties 90% to year 12, which is 2 years longer than the standard.
4. Every other solar company is the standard – 90% at year 10, and 80% at 25.

Here is a chart comparing the solar output warranties of 10 major companies. Click to enlarge.

Lastly, solar panels will last for more than 30 years. They were originally designed to withstand the conditions in space and to be used in remote places without electricity access. There are no moving parts in a solar panel. The cells are encased in metal and glass frames designed to withstand hurricane winds, rain, hail and other extreme weather conditions.

Martin Holladay bought a panel back in 1980 that was manufactured in 1979. In 2010, he tested the output of his solar panel for the 30 year anniversary. It performed better than expected, returning 97% of the original voltage and more amps than the spec sheet said it should output originally. You can read more here.

Solar will last a long time. Expect a 2% decrease when you install them, and then a reasonable 0.5% per year after that. Let’s hope this article helps improve the 2011 industry standard warranties.

Solar Manufacturer Warranty Documents

Notes: 1. Trina Solar has two different warranties for Mono and Poly modules.
2. Manufacturers were chosen based on 2010 market share and name recognition.

1. Suntech - 2011 and 2010
2. JA Solar
3. First Solar
4. Yingli Solar
5. Trina Solar
6. Sharp
7. Canadian Solar
8. Sanyo Electric – HIT Series
9. Sunpower Solar
10. SolarWorld

Related Articles:

1. Solar Efficiency Losses Over Time - Chart comparing solar manufacturer warranties and explanation of how much you can expect solar output to decrease over time.