Poor Lloyd

Normally I don't like to talk about stories from other blogs, but this

one really caught my attention. Slashdot put out a story on Lloyd Case. A geek in Northern

California who installed a 6kW PV solar system on his house six months

ago and is now a little disappointed with the performance. His most

recent power bill was still $200 despite having a $60,000 PV setup

tied to the grid.

 

A few tips to folks who are considering a PV system.

 

1. Roof Mounted Panels Suck - They often have limited or no tilt

control and clumsy to maintain. This means that you will likely get

strong performance in summer or winter, but not both. Finding the

average latitude tilt for your region and mounting the panels at that

angle is your best option for roof mount. Trackers can bring your

performance up by 1/3rd, but will include extra expense and

complexity. Consider a manual tracking system which you just push with

your hands through out the day if you need a early morning or late

afternoon boost. This is ideal for the off-grid / unemployed eco-geek.

 

2. Grid Tie has issues too - Although grid-tie allows a PV install to

greatly reduce their installation time and costs they also have some

drawbacks. Continuing to buy power from a power company can result in

relatively high monthly fees if the system purchased was undersized.

Many grid-tie installations have no battery backup so when the grid

dies, you lose all your juice too. In remote towns many power

companies only pay the customer a 1/4 of what they charge the customer

for power. My town being unusually behind the times refuses to

purchase any power from their customers.

 

3. PV Batteries - New batteries are easy, but old ones can be fixed.

Our world is hemoraging so called "dead cycle batteries". Try talking

to your local golf course, marina, or auto parts store. As you learn

to test cells and repair lead acid batteries through desulfation you

can save yourself a fortune in batteries and store large amounts of

energy. Keep in mind that batteries are much like people. They like

72F temperatures and a little exercise. Do not cycle the batteries

below 50% on a regular basis. I try to stay over 70% capacity on my

battery array at all times.

 

4. Heat - My panels tend to have a pretty big drop off in performance

during the summer. This is partly due to my not adjusting the PV array

to be almost flat during June. It is also related to our monsoon

season bringing in lots of rain and cloudy weather. However, the real

killer of performance is the temperature. High temperatures drop my

panel performance by 30%. Our temps in June sit peak around 100F in

June which is enough to dramatically reduce the performance on a

polycrystal PV cells. The monocrystal cells are supposed to handle the

higher temperatures better.

Done