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electrical:solar:pvwatts [2023/06/16 13:22] frater_secessus [how much panel do I need to make X watt-hours?] |
electrical:solar:pvwatts [2023/06/17 13:33] frater_secessus [SYSTEM INFO] pwm efficiency clarification |
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You can use [[https:// | You can use [[https:// | ||
- | - find out how much power your | + | - find out how much panel is required to make a certain amount of Watt-hours (Wh) daily; or |
+ | - find out how much power your existing solar setup can make | ||
- | ===== how much energy can my system harvest? ===== | + | ===== how much panel do I need to make X watt-hours? ===== |
- | ==== choose a location | + | ==== GET STARTED |
- | First, pick a location using the search bar: | + | First, |
{{https:// | {{https:// | ||
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==== SOLAR RESOURCE DATA ==== | ==== SOLAR RESOURCE DATA ==== | ||
+ | This page shows you the location it selected. | ||
- | ==== system info ==== | + | ==== SYSTEM INFO ==== |
- | We need to make a couple changes here | + | Change TILT to 0, and accept the other defaults on this page. The other settings won' |
- | * your array size in **kW**. | ||
- | * accept the default losses for MPPT systems. | ||
- | * if your panels are flat (most are) adjust tilt to zero | ||
+ | ==== RESULTS ==== | ||
- | {{https://img.mousetrap.net/ | + | The results has three columns: |
+ | ==== using the results ==== | ||
+ | Run the arithmetic below, using 0.85 for overall system efficiency with MPPT and 0.7 with PWM. | ||
+ | Wh required / "Solar Radiation" | ||
+ | ==== example ==== | ||
- | ==== results ==== | + | [[https:// |
- | The first column is kWh/square meter/**day**, AKA Hours of Full Sun Equivalent (FSE). | + | You need 900Wh/day. You live in Stuttgart, Germany and the lowest |
- | The second column is kWh harvested per **month**. To find average maximal harvest per day divide this figure by the number | + | So 900Wh / 2.37 / 0.85 = **446.76w** of flat-mounted panel. Round up to 450w or 500w, whatever is available. |
+ | | ||
- | Example: | ||
- | {{https:// | ||
- | Note: the 2nd column is //rounded to whole numbers// | ||
- | FSE x array wattage x ((100 - system losses) / 100) | ||
- | | ||
- | ...which gives a more precise **605Wh/ | ||
- | | ||
- | | ||
- | ===== how much panel do I need to make X watt-hours? ===== | ||
- | - pick your location in PVwatts [[:# | ||
- | - accept the default system | ||
- | - select the "Solar Radiation" | ||
- | - run the arithmetic below, using System efficiency will be 0.85 for system efficiency with MPPT and 0.7 with PWM. | ||
- | Wh required / "Solar Radiation" | ||
- | ==== example ==== | ||
- | [[https:// | ||
- | You need 900Wh/ | ||
- | So 900Wh / 2.37 / 0.85 = **446.76w** of flat-mounted panel. | ||
- | | ||
- | | ||
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+ | ===== how much energy can my system harvest? ===== | ||
+ | ==== GET STARTED ==== | ||
+ | First, pick a location using the search bar: | ||
+ | |||
+ | {{https:// | ||
+ | |||
+ | === SOLAR RESOURCE DATA === | ||
+ | |||
+ | |||
+ | This page shows you the location it selected. Accept the default unless it needs correcting. | ||
+ | ==== SYSTEM INFO ==== | ||
+ | |||
+ | We need to make a couple changes to the defaults here: | ||
+ | |||
+ | * your array size in **kW**. | ||
+ | * accept the default losses for MPPT systems. | ||
+ | * if your panels are flat (most are) adjust tilt to zero | ||
+ | |||
+ | |||
+ | {{https:// | ||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | ==== RESULTS ==== | ||
+ | |||
+ | The second column is kWh/square meter/ | ||
+ | |||
+ | The third column is kWh harvested per **month**. To find average harvest per day divide this figure by the number of days in that month. | ||
+ | |||
+ | Example: | ||
+ | |||
+ | |||
+ | {{https:// | ||
+ | |||
+ | Note: the 3rd column is //rounded to whole numbers// | ||
+ | |||
+ | FSE x array wattage x ((100 - system losses) / 100) | ||
+ | | ||
+ | ...which gives a more precise **605Wh/ | ||
+ | | ||
+ | | ||