Announcement

Collapse
No announcement yet.

I just discovered panels will get shade, change build?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Originally posted by J.P.M. View Post

    And not an irradiance hot spot. Thank you.
    I don't understand. Can you explain?

    Comment


    • #17
      Originally posted by crashintoty View Post

      I don't understand. Can you explain?
      My guess is that you don't need suntan lotion as much as someone in San Diego. (Depending on the altitude.)
      9 kW solar, 42kWh LFP storage. EV owner since 2012

      Comment


      • #18
        Originally posted by crashintoty View Post

        I don't understand. Can you explain?
        Seattle will not get much sunlight to properly use solar.

        Comment


        • #19
          Originally posted by SunEagle View Post

          Seattle will not get much sunlight to properly use solar.
          The following site may be suspect since it has ads for solar referals but here is an opinion.

          solar energy local website google it if interested

          In summary, Seattle gets 3.5 versus Sacramento Ca which gets 5.5. What that tells me is you could compensate by adding more panels, with the obvious increase in payback time. If I remember correctly Washington had inexpensive hydro power for a long time but that may no longer be the case.

          Admin note, I didnt like that link so I removed it
          Last edited by Ampster; 02-28-2020, 02:13 PM.
          9 kW solar, 42kWh LFP storage. EV owner since 2012

          Comment


          • #20
            Originally posted by SunEagle View Post

            Seattle will not get much sunlight to properly use solar.
            Oh, I didn't know there was a minimum requirement. What constitutes properly used solar?

            Comment


            • #21
              Originally posted by crashintoty View Post

              Oh, I didn't know there was a minimum requirement. What constitutes properly used solar?
              I have some improperly used solar. I self installed ten used SunPower panels on my patio cover that face west, are shaded sometimes and only produce 3 or 4 kWhrs per day. If I had properly installed them They would have produced 10 kWhrs per day.
              9 kW solar, 42kWh LFP storage. EV owner since 2012

              Comment


              • #22
                Originally posted by crashintoty View Post
                Oh, I didn't know there was a minimum requirement. What constitutes properly used solar?
                Cost effectiveness vs Greenwashing. If it takes you 35 years for payback on an array that would even out in 10 years, you have to consider if it's a good use of your dollars, or if simply conserving has a better payback.

                Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
                || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
                || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

                solar: http://tinyurl.com/LMR-Solar
                gen: http://tinyurl.com/LMR-Lister

                Comment


                • #23
                  My ten used panels cost $900 and earn me $400 a year in credit at Peak TOU rates.
                  9 kW solar, 42kWh LFP storage. EV owner since 2012

                  Comment


                  • #24
                    Originally posted by crashintoty View Post

                    Oh, I didn't know there was a minimum requirement. What constitutes properly used solar?
                    There really isn't a minimum requirement but for pay back calculations I would think you want to get as much useful sunlight as possible for a pv system.

                    Comment


                    • #25
                      Originally posted by Ampster View Post
                      My ten used panels cost $900 and earn me $400 a year in credit at Peak TOU rates.
                      Just remember that most people live in states other than CA where solar credits are slim to none.

                      But then again I pay less than $0.10/kWh for power so I am not sure who is ahead in this race.
                      Last edited by SunEagle; 02-26-2020, 12:25 AM. Reason: added last statement

                      Comment


                      • #26
                        No race intended. I was having some fun with the notion that there was a "proper" way to use solar. Last time I checked the energy from the sun was free and California doesn't have any solar credits.
                        These guys say it is worthwhile having solar in Florida. Who to believe?
                        https://www.solarreviews.com/blog/so...-savings-guide
                        Last edited by Ampster; 02-26-2020, 02:57 AM.
                        9 kW solar, 42kWh LFP storage. EV owner since 2012

                        Comment


                        • #27
                          Originally posted by crashintoty View Post

                          I don't understand. Can you explain?
                          I'll try. Short answer: Seattle doesn't get a lot of solar energy relative to most other places on the earth's surface.

                          Read the rest of this post if you're curious and want a bit of context.

                          The more sunshine a location receives, the better are the economics for solar energy utilization and the easier it is to meet a duty using solar energy devices. Such locations places have fewer clouds.
                          The less sunshine a location receives, the less favorable are the economics for solar energy utilization and the harder it is to meet a duty using solar energy devices. Such locations tend to be more cloudy.

                          As my esteemed colleague Ampster so insightfully notes (and as others have done for longer than I've been into solar energy), sunshine is indeed free. However, the equipment and means to get at the free energy are not (free).
                          I'd also note that the oil seeping out of the ground and used by the Native Americans at a place called Oil Creek was also free. Edwin Drake saw that and came up with oil drilling. The drilling process and the equipment were not free.
                          For most fuels including fossil, nuclear and hydro - the source of most of the power for energy producing equipment, the harder it is to get the fuel, the more costly the fuel becomes. And, the equipment that turns the potential energy contained in the fuel into kinetic energy also has a capital cost.
                          So it is with solar energy. Less sunshine makes the solar fuel harder to get (less available). That tends to make the equipment larger and so also more expensive than in places where the sun shines a lot (more).

                          One pretty objective (but I'd carefully note, not linear) measure of how suitable an area is for solar energy utilization used by folks trying to figure out ways to utilize all the free energy is to use something called the "Clearness Index", often abbreviated as "C.I."

                          C.I. at a location == (Global Horizontal Insolation at ground level at a location)/(Extraterrestrial Insolation at the same spot on the globe, parallel to the earth's surface at that point, but above the earth's atmosphere). Both quantities are measured over the same time period, be it a second, hour, day, month year, whatever time period is called for.

                          For the contiguous U.S. the annual C.I. varies from ~ 0.48 or so for parts of the Pacific NW and much of the NE U.S., particularly around the Great Lakes.
                          Examples:
                          Seattle : Ave. annual C.I. ~ 0.48, lowest month ~ 0.26, highest month ~ 0.63 ( that 0.63 looks like something of an anomaly, next highest month is 0.53)
                          Buffalo: Ave. annual C.I. ~ 0.49, lowest month ~ 0.27, highest month ~ 0.50

                          Places with lower annual C.I.'s tend to have a lower summer C.I. with the summer - winter spreads relatively large.

                          Sunnier places have higher C.I's
                          Examples:
                          Albuquerque: Ave. annual C.I. ~ 0.65, lowest month ~ 0.63, highest month ~ 0.73
                          San Diego (airport): Ave. annual C.I. ~ 0.60, lowest month ~ 0.56, highest month ~ 0.62

                          Sunnier places also seem to enjoy less seasonal (S -W) variation in the C.I.

                          C.I. is one tool to gauge how sunny an area is.
                          Another is to use ave. monthly or ave. annual G.H.I. per day as measured in kWh/m^2/day.
                          Neither tool is ideal. Careful interpretation of what the numbers are saying is necessary.

                          FWIW, I've lived in 3 of the above 4 places. IMO only, living in irradiance hot spots (places with more sunshine) is better. And, if economics are of any consideration, it's a whole lot easier to make solar energy competitively cost effective (if it's possible at all) in places with high(er) C.I's.

                          Comment


                          • #28
                            Originally posted by Ampster View Post
                            No race intended. I was having some fun with the notion that there was a "proper" way to use solar. Last time I checked the energy from the sun was free and California doesn't have any solar credits.
                            These guys say it is worthwhile having solar in Florida. Who to believe?
                            https://www.solarreviews.com/blog/so...-savings-guide
                            I guess the word "race" is not appropriate. What I meant was that with our low electric rates it is very hard to justify solar in Florida. My calculations put my ROI out beyond 10 years. But I will probably spend much less for power then those in CA with solar.

                            As for websites that try to encourage solar in Florida, I think you have to understand who gains and who loses on that stage. Some of the local adds still have that 30% credit from the FED's so I think they are just trying to convince the people not really aware of the costs that the Sun is "free" which it isn't.

                            Comment


                            • #29
                              Originally posted by J.P.M. View Post

                              I'll try. Short answer: Seattle doesn't get a lot of solar energy relative to most other places on the earth's surface.

                              ..............
                              FWIW, I've lived in 3 of the above 4 places. IMO only, living in irradiance hot spots (places with more sunshine) is better. And, if economics are of any consideration, it's a whole lot easier to make solar energy competitively cost effective (if it's possible at all) in places with high(er) C.I's.
                              I agree that there are places that are better for solar than others. I also agree the cost of the equipment goes up as the irradiance in a location goes down, Unless the OP has the option or desire to move to a sunnier climate, he has to weigh those additional costs against the benefits. Those are the economics that matter to most people who choose to live where they live.

                              The context of the title of this thread is clouds and what to do about that. That is what the OP asked about and what I will try to answer by using some examples of what might be considered by others to be improperly used solar.

                              A quick read through other threads where the author of those threads encountered similar issues leads to the conclusion that one solution is to over-panel. For example, @bcroe, lives in rural Illinois with plenty of land and the ability to do some work by himself. He has built a system that has a DC to AC ratio in excess of 2 to one. He has also oriented his arrays to gather the available irradience over a longer period of time. As a result when measured by the capacity of his inverters he is producing close to 2000 Watts per Watt of installed inverter capacity. That compares favorably to the 1200 to 1500 Watts per Watt of capacity that I get at several locations in sunny California.

                              My tongue in cheek response to your question about what constitutes properly used solar was intended to illustrate that there are a lot of different opinions about how to skin a cat and as far as I know there is no standard that would be considered proper. The responses to your question clearly illustrate that phenomena.

                              In my case I had an existing grid tied system with a capacity of 5.7 kWs. I also had a west facing patio that could use some shade. I have carpentry skills and a good understanding of appropriate spans of lumber, so I built a west facing patio structure with the idea of covering it with solar panels. I found some used solar panels that were a little more expensive than the plastic material that is typically used for patio covers. This was clearly not the best location for solar since I had plenty of south facing roof area. It did provide the shade I sought and the home was cooler in the afternoon so my Air Conditioning use was reduced. From a solar production standard, using the metric I referred to above, it probably only produces 300 to 400 Watts for every Watt of installed capacity but it met my goals even though most people would consider it sub optimal.

                              In both cases I think these examples met the standard suggested by Mike. They produced reasonable paybacks and importantly met the goals of their owner. I hope you are encouraged by these examples to keep tinkering.
                              Last edited by Ampster; 02-26-2020, 02:43 PM.
                              9 kW solar, 42kWh LFP storage. EV owner since 2012

                              Comment


                              • #30
                                Originally posted by Ampster View Post
                                In my case I had an existing grid tied system with a capacity of 5.7 kWhrs.
                                Is that a typo ?

                                Comment

                                Working...
                                X