Plant Care
- • Climate Control & VPD16
- • Disease & Pest Management14
- • Nutrient Solutions & EC34
- • Plant Health Monitoring7
Inputs
10 parameters · live recalculation on every change
W
100W
1000W default
10000W
W
10W
200W default
2000W
W
10W
100W default
1000W
H/DAY
12h/day
18h/day default
24h/day
$/KWH
0.05$/kWh
0.15$/kWh default
1$/kWh
Pro Settings — Lab Controls
%
5%
20% default
40%
Advanced Settings — Deterministic Corrections
H/DAY
1h/day
5h/day default
10h/day
W
100W
400W default
1000W
V
12V
48V default
96V
%
50%
80% default
90%
Insight band · live
Building the daily draw
Lighting, pumps and fans add up to the daily draw the solar array must recharge — the running total lands on the draw.
- Lighting 18.0 18.00 kWh
- + Pumps 3.6 21.60 kWh
- + Fans 1.8 23.40 kWh
- Daily draw 23.4 23.40 kWh
Panels: 15
Battery: 29.2 kWh
Running total after each term — the final net matches the headline reading in the result card, kept in sync live.
Deterministic model
10 inputs · 10 outputs
Runs 100% in your browser
This is a deterministic model: the same inputs always produce the same outputs, calculated entirely in your browser with nothing sent to any server. It is a planning aid — not a quote, not a dosing instruction, and not a yield forecast. Treat every line as a working estimate and validate it against your own prices and measurements.
It models one system: The Pro-level electricity and autonomy blueprint for a grow room. Enter the lighting, pump and fan wattage with run hours and the engine returns the daily and monthly kWh draw, the utility bill at your rate, the exact solar panel count your peak-sun hours and wiring losses demand, the battery bank in kWh and amp-hours held against depth of discharge, the 1.25x inverter rating with its continuous-load safety read, and the annual carbon footprint at 0.4 kg CO2 per kWh.
What the Energy Load & Solar Microgrid Sizer — Load, Solar & Cost Blueprint returns
The engine computes 10 outputs from your 10 inputs. The headline number is Daily Energy (kWh/day), alongside Monthly Energy, Monthly Cost, Solar Panels. Every output updates live as you change a parameter.
What it does not do
Outputs depend on the inputs and assumptions shown here. Confirm relevant measurements and local conditions before acting.
STEP 01
Sum the system wattage — total watts = light + pump + fan. Pumps and fans often run 24 h/day, so their daily share rivals the lights.
STEP 02
Compute the daily energy: total watts × run hours ÷ 1000 = daily kWh. That single number is the whole load story.
STEP 03
Scale to the month (× 30) and bill it (× rate) for the monthly cost, then fold in the annual CO2 at 0.4 kg/kWh.
STEP 04
Size the battery from the daily draw against your depth of discharge: bank kWh = daily ÷ (DoD/100), then convert to amp-hours at the bus voltage.
STEP 05
Size the solar array so it recharges the daily draw inside peak sun hours after system losses: panels = daily kWh ÷ (sun hours × panel watts × (1 − loss/100)).
STEP 06
Size the inverter at 1.25x the continuous load so the draw sits at 80% of rating, and read the safety and cost bands from the load and the bill.
E_{daily} = \frac{(P_{light} + P_{pump} + P_{fan}) \cdot h_{run}}{1000}
Daily energy — the summed system wattage across the run hours, expressed in kWh
E_{month} = E_{daily} \cdot 30
Monthly energy — a 30-day billing month scales the daily draw
C = E_{month} \cdot r \qquad (r = \text{rate } \$/kWh)
Monthly cost — energy billed at your blended utility rate
N = \left\lceil \frac{E_{daily} \cdot 1000}{H_{sun} \cdot P_{panel} \cdot (1-\tfrac{L}{100})} \right\rceil
Solar panels — the daily kWh must be recharged inside peak sun hours after wiring/inverter losses
B_{kWh} = \frac{E_{daily}}{\frac{DoD}{100}}
Battery energy — the daily draw grossed up by depth of discharge so the bank is never flattened
Ah = \frac{B_{kWh} \cdot 1000}{V_{system}}
Battery amp-hours — bank energy converted to capacity at the bus voltage
P_{inv} = P_{total} \cdot 1.25 \qquad \Rightarrow \, \text{continuous load } = 80\%
Inverter sizing — 1.25x the continuous load holds the draw at 80% of rating, the safe running margin
m_{CO2} = E_{month} \cdot 12 \cdot 0.40 \quad \left(\tfrac{\text{kg CO}_2}{\text{kWh}}\right)
Annual carbon footprint — monthly energy across the year at the ~0.4 kg CO2/kWh grid planning average
Load math: total watts = light + pump + fan, then daily kWh = watts × hours ÷ 1000. A 1,000 W light over 18 h is 18 kWh/day alone — the pure arm the scenario checks confirm.
Solar sun hours are not daylight hours — they are 1000 W/m²-equivalent hours. A 5 PSH site turns a 400 W panel into ~2.0 kWh/day before losses, ~1.6 kWh at a 20% loss budget.
Depth of discharge decides the bank: LiFePO4 tolerates 80%, lead-acid must rest near 50%. Deeper DoD shrinks the bank but shortens cycle life — size for the chemistry you run.
The inverter carries the load at 80% of its rating when sized 1.25x — the same continuous-load margin as the NEC 80% rule. Below 80% you have surge headroom for pump startups at 2–3x running watts.
System loss at 20% folds in wiring resistance, inverter conversion and charge-controller losses. Hot installs and long DC runs push it higher — derate to 25–30% and the panel count rises with it.
CO2 at 0.4 kg/kWh is the US grid planning average; spot emissions vary by region and time of day. Multiply your monthly kWh by your local marginal rate for a truer footprint.
- Load: total watts = light + pump + fan; daily kWh = total watts × run hours ÷ 1000, and continuous loads must stay at or below 80% of the breaker or inverter rating (the NEC / inverter 80% rule).
- Solar: panels needed = daily kWh ÷ (peak sun hours × panel watts × (1 − wiring/inverter loss)); the array must recharge the daily draw inside the sun window.
- Battery: bank kWh = daily kWh ÷ depth of discharge; amp-hours = bank kWh × 1000 ÷ system voltage. LiFePO4 runs at 80% DoD, lead-acid at 50%.
- Cost: monthly cost = monthly kWh × rate; CO2 ≈ 0.4 kg CO2 per kWh of grid electricity — the EPA/US-grid planning average.
This model combines the earlier Electrical-load, Solar-battery-sizer, Energy-cost-simulator, Running-cost-calculator models.
Q1: How much electricity does a grow room use per day? ▾
Daily energy is total system wattage (lights + pump + fans) multiplied by run hours and divided by 1,000. A 1,000 W light over an 18 h photoperiod is 18 kWh/day on its own; adding a 200 W pump and a 100 W fan on the same timing brings a 1,300 W system to about 23.4 kWh/day. The engine sums every load first, then integrates the day — so the daily kWh number is the honest full-circuit draw, not just the light.
Q2: How many solar panels do I need to run my grow? ▾
Divide your daily kWh (in watt-hours) by what one panel delivers in a day: peak sun hours × panel watts × (1 − system loss). On a 5-sun-hour site a 400 W panel produces about 1.6 kWh/day after a 20% loss budget, so a 23.4 kWh/day grow needs roughly 15 panels. Fewer sun hours or losses above 20% raise the count — and over-sizing slightly buys cloudy-day recovery.
Q3: What battery bank size do I need for off-grid backup? ▾
Size the bank to hold a full day of draw at your depth of discharge: bank kWh = daily kWh ÷ (DoD/100). A 23.4 kWh/day grow on LiFePO4 at 80% DoD needs about 29.3 kWh (610 Ah at 48 V); lead-acid at 50% would need nearly double. The DoD buffer is the difference between a bank you can drain and a bank you destroy.
Q4: Why is the inverter sized at 1.25x the continuous load? ▾
Inverters, like breakers, must run below their nameplate continuous rating. Sizing at 1.25x the load parks the draw at exactly 80% of the inverter rating — the same continuous-load margin as the NEC 80% rule — leaving headroom for pump startup surges that can spike to 2–3x running watts. A 1,300 W grow therefore gets a 1,625 W inverter, and the safety read turns yellow at that 80% running point by design.
Q5: What does the 20% system loss represent? ▾
The 20% default is the full-chain loss budget between the panel and the load: wiring resistance on long DC runs, inverter AC conversion, and charge-controller losses, plus a temperature derate on hot panels. It concerns the yield of every panel you install. Hot roofs and distant battery banks push the true figure higher — derate to 25–30% there and the panel count climbs accordingly.
Q6: What is the carbon footprint of my grow, and how is it estimated? ▾
Emissions are monthly kWh × 12 × 0.4 kg CO2 per kWh. On a 702 kWh/month grow that is about 3.4 tonnes of CO2 per year — roughly the footprint of a small car. The 0.4 kg/kWh is the US grid planning average; if you live in a coal-heavy region or run at peak hours the real number is higher, and solar reclaims it at the panel.