Overview
Live results for the current inputs. Update after changing any field below.
Every result is traceable to inputs and equations. Historical averages do not guarantee future weather or system output.
Site & climate data
Pick a location on the map, then fetch NASA POWER irradiation and temperature.
1 Location & climate data
Click the map, search a place, or enter coordinates. The location label updates automatically.
2 Solar resource summary
From the selected NASA POWER period.
| No resource data yet. |
3 System losses & performance ratio
PR is built from individual loss factors. Module efficiency ≠ system efficiency.
Solar resource
Monthly and daily irradiation from the selected NASA POWER period.
4 Monthly solar irradiation
kWh/m² per month from daily totals.
5 Daily irradiation (GHI vs POA)
Horizontal vs plane-of-array estimate (isotropic-sky transposition).
System design
Configure the PV array and electricity demand. Press Recalculate in the bottom bar when done.
6 PV system configuration
Mode A: fixed capacity · Mode B: size from demand.
7 Electricity demand
Total daily energy, or a component-based load list. Examples are illustrative and editable.
Generation vs demand
Seasonal and daily energy balance. Annual surplus does not prove uninterrupted supply.
8 Monthly generation vs demand
Seasonal deficits can hide behind a healthy annual total.
9 Daily generation vs demand
Daily resolution from NASA POWER irradiation.
10 Cumulative energy balance
Running surplus (generation − demand).
11 Monthly temperature profile
Used by the temperature-adjusted PV model.
Storage (optional)
Battery sizing and approximate daily state of charge. Daily SOC is not a reliability guarantee.
12 Battery & storage sizing
First-order autonomy: Autonomy = Usable energy / Daily load. Daily SOC simulation is approximate.
13 Storage state of charge
Approximate SOC from daily energy balance.
| Enable storage and calculate. |
Economics & LCOE
Optional financial assessment — all prices are your inputs or labelled examples.
14–17 Cost inputs & results
Replace example prices with local quotes. Click Compute economics after editing.
14 Cost inputs
Replace example values with local quotes before any decision.
15 LCOE & payback results
16 LCOE sensitivity
Discount rate × electricity tariff.
17 Monthly energy balance
| Month | POA | Gen (kWh) | Demand | Balance | Coverage |
|---|
Solar power plant designer
Domestic rooftop and utility-scale array layout, clipping, and plant economics (approximate screening model).
P Array architecture & plant economics
Domestic rooftop and utility-scale array layout, clipping, and plant economics (approximate screening model).
Plant scale
Choose a domestic rooftop system or a utility-scale power plant. Defaults adjust to the selected scale.
The suggestion is a regional screening heuristic driven by the NASA POWER context you already loaded (latitude, annual GHI, and mean temperature) plus the selected scale (Domestic or Utility). Tilt is set near latitude (reduced for trackers); azimuth faces the equator; tracker type follows the latitude band; DC/AC ratio follows irradiance level; capacity, row pitch/GCR, soiling, and example CAPEX/O&M/PPA follow the same rules. Values are written into the form so you can review and override every field. This is not a yield study or a procurement recommendation.
P1 Array architecture
String layout, inverters, and DC/AC ratio.
P2 Plant energy & economics
Screening LCOE and revenue under a stated PPA/tariff. Prices are your inputs.
Equations & assumptions
Every result is traceable to these formulas and the inputs you set.
18 Equations & assumptions
E_PV = P_STC × H_POA / G_STC × PR
PR = ∏(1−L_i) × η_inv × η_avail
H_T ≈ H_b·R_b + H_d(1+cosβ)/2 + H·ρ(1−cosβ)/2
P_kWp = E_day / (H_POA_day × PR)
T_cell ≈ T_amb + (NOCT−20)/800 · GP = P_stc(1 + γ(T_cell − 25))
Days = Usable_kWh / Daily_load_kWh
LCOE = (I₀ + Σ OPEX_t/(1+r)ᵗ) / (Σ E_t/(1+r)ᵗ)
t* ≈ I₀ / (Annual savings − OPEX)