Grid-tied solar

[MossRoad]

^^^ thanks for posting the story...

I've made some minor adjustments at the hospital to minimize the demand factor such as staggering start time for the HVAC systems... so not everything starts at 5 am in the morning causing a peak for power usage during a 15 minute interval.

Amazing what timers can do! :laughing:

We had air compressors, and HVAC simultaneous starting issues for a while. Staggered the start times. All O.K. :thumbsup:

 

[dave1949]

US lower 48 annual solar insolation by county, 1979-2011, in an interactive map. Also insolation maps by month.


Map: Where America’s sunniest and least-sunny places are - The Washington Post

 

[houstonscott]

45 kWh in May - you will see higher output once the sun angle changes in the spring and fall Today we have exceeded 40 kWh and in Monday too do a good month so far

Carl, how often do you clean your panels. Mine seemed to look dusty so a hosed them off, how much can dirt and dust effect production. I use rainX on my cars and it makes the glass so slick almost nothing sticks to it, I'm thinking of putting rainX on my panels to keep them clean. HS

 

[Redneck in training]

Carl, how often do you clean your panels. Mine seemed to look dusty so a hosed them off, how much can dirt and dust effect production. I use rainX on my cars and it makes the glass so slick almost nothing sticks to it, I'm thinking of putting rainX on my panels to keep them clean. HS

I have three banks of PV panels and I live on a gravel road so dust on panels is way of life here. It also provides for easy experiment when I will wash only one bank and compare the performance. I just washed one bank and I have to report that small amount of dust (about 4 days after last rain worth) cuts about 3-4% of production.

 

[Redneck in training]

Here is and article about distributed energy storage. I think that is a beginning of change how we generate and use energy.
Falling energy storage costs and steadily increasing solar capacity stand to catalyze a paradigm shift from net metering to distributed energy storage.

 

[houstonscott]

I have three banks of PV panels and I live on a gravel road so dust on panels is way of life here. It also provides for easy experiment when I will wash only one bank and compare the performance. I just washed one bank and I have to report that small amount of dust (about 4 days after last rain worth) cuts about 3-4% of production.

That's significant. I'll keep them clean. HS

 

[houstonscott]

Here is and article about distributed energy storage. I think that is a beginning of change how we generate and use energy. Falling energy storage costs and steadily increasing solar capacity stand to catalyze a paradigm shift from net metering to distributed energy storage.

We need that battery breakthrough. That would be a game changer. HS

 

[Carl_NH]

I have three banks of PV panels and I live on a gravel road so dust on panels is way of life here. It also provides for easy experiment when I will wash only one bank and compare the performance. I just washed one bank and I have to report that small amount of dust (about 4 days after last rain worth) cuts about 3-4% of production.

HS - I hose them down so far 2 times when we had a lot of pollen on them and no rain

I couldn't see a huge difference with the pollen but it I can tell you snow covering and part of the panel it does impact production

Carl

 

[KiwiBro]

Is everybody clear on the difference between feed in tariff and grid tie ?

Would be great to have this explained please. Here, the buy-back rates vary between power co's (there are no mandated feed-in tariffs) and, alarmingly, they won't be locked into any significant periods. The only way it stacks up financially here at the mo' seems to be when the cost of connecting to the grid is prohibitive. Looking out my window, there's a house and shed/workshop building site I'd like to relocate buildings to, that will cost $60k to get power connected.

We had a power cut here two nights ago. I made a point of looking out across the whole valley. There was just one house that still had lights on.

 

[Redneck in training]

Would be great to have this explained please. Here, the buy-back rates vary between power co's (there are no mandated feed-in tariffs) and, alarmingly, they won't be locked into any significant periods. The only way it stacks up financially here at the mo' seems to be when the cost of connecting to the grid is prohibitive. Looking out my window, there's a house and shed/workshop building site I'd like to relocate buildings to, that will cost $60k to get power connected.

We had a power cut here two nights ago. I made a point of looking out across the whole valley. There was just one house that still had lights on.

If I understand it correctly GB (and most likely other European countries) has feed in tariff (FIT). If the system is 4kW DC or less the current rate is 50% of estimated production that is used to offset energy charge. Since it is not measured (Yet) people use various devices that redirect excess energy generated by the PV to in example hot water immerSUN | immerSUN. The goal is not to supply any energy to grid but lower consumption of in example natural gas used to heat the water. If the system is larger than 4 KW the the FIT rate decreases. Some European members might give us more precise description I suppose.

Most large utilities that are regulated by states have to offer some version of net metering in the USA. Some are settled monthly and some yearly. In any case utility will install "smart" meter that keeps track about energy consumed and energy pushed to the grid. Whatever is pushed to the grid is accumulated and used to offset energy consumption when sun is not shining. If you still have excess then utility will pay you the wholesale rate (typically 0.035 USD/kWh) or it will just pocket the energy and give you nothing. Settling the account once a year produces the best results because summer generation excess is used to offset winter deficit. Some utilities charge a "connection" fee to clients with PV. Some small utilities (electric cooperatives) that are not regulated by the states are very supportive of alternative energy and provide net metering, grants, loans etc, some are indifferent and some are openly hostile and punish you in example by canceling so called heating rate (if you have geothermal or high efficiency heat pump heating) that is less than half of retail rate (0.048 versus 0.115 USD) increasing your energy billing by several hundred dollars/year.

You can look at net metering as a battery with 100% charge/discharge efficiency. Net metering provides for short ROI especially if you can shift energy load to electric in example you switch from oil fired boiler to a heat pump.