Most solar installers will charge by the watt capacity of your system. This will run you about $7/watt, plus or minus a buck or so depending on where you live. So, for a “3kW” system (which is the number everyone always throws around) you are talking about $21,000. That’s BEFORE incentives, however. To make it confusing, every state has a different subsidy system for solar (which they shouldn’t). You need to learn what the specific solar incentives are in your state to really know what your final (net) price is going to be. But hey, that’s what we’re here for!

To make it even more confusing, solar contractors will add costs for certain things (most are reasonable while some are not). Standard Solar, on the other hand, has standardized their pricing. It seems to be working for them as they are doing quite well. While I’d like to see things move in that direction, here are 9 things you should be aware of which may inflate your cost of going solar:

1. Flat Roof Tilting. If your roof is flat, you must build some scaffolding to tilt it up towards the sun. That framework costs some money.

2. Different Roof Types. Some are harder to seal or flash, or find studs. Accordingly, some installers will charge more based on your roofing material. see more here

3. Distance. If you reside outside the regular service area of your nearest installer, there may be associated travel fees that will be passed on to you.

4. Monitoring Systems. Some solar companies sell monitoring systems which upload data about your solar energy production to the web. If these interest you, expect to pay a little more.

5. Trenching. Does conduit need to be run underground to near your meter? There may be a fee for that. This type of activity is generally associated with ground mounted systems… which brings us to….

6. Ground Mounts. If your system is installed in your backyard instead of on your roof, not only does your contractor have to build the framework but also secure it to the ground. That usually means concrete. Concrete, building a frame, and securing it to the ground costs money. Therefore, this type of installation is usually more expensive than installing a system on your roof. The upside? You get to aim and tilt the panels optimally for your region, whereas on a roof you are bound by the direction your home is already pointed.

7. Permits. Your region may have much trickier or more expensive building permits than the installer is used to. Therefore, you can expect higher fees for this.

8. Inverter Upgrade. Let’s say you want to install more solar down the road. Therefore, you could opt to purchase a beefier inverter to accommodate your planned upgrade for some extra money. For example, you might want to take advantage of utilities being required to pay for excess yearly production sometime in the near future. Currently they are not required to.

9. Service Upgrade. The inverter (the thing that makes the unusable DC current your solar panels produce into usable AC current for your home appliances) is like an appliance itself. It will need to be connected in your main breaker panel and there may not be space for it. This can create an issue and an electrician may need to install a sub panel, or your utility may need to upgrade your service (for example, from 100 to 200 amp service). You can tell what service you have by looking at the door to your main breaker panel, it should say (MAX AC) somewhere.

Now the fun stuff: DISCOUNTS!

• Employee Discounts. Aside from the state rebates, you may qualify employee discounts. For instance, if you work for HP, Google, or SunPower, you get a discount. Check with your employer!

• Group Purchase discounts. This is where many people get solar at once. Solar companies are going to start exploring this business model soon, but for now you can do it yourself if you have friends that are interested. If you call up an installer and have five serious customers in the same neighborhood, you can seriously lower overhead for the installer, and they can pass those savings on to you. Approach the installer about it.

Bottom line – don’t freak out about all this. The salespeople for your local solar company know their stuff and can explain all of it to you in better detail.