The battery keeps grid demand under one set limit, all day. Even the best single limit for this site (66 kW, chosen with hindsight) leaves the month billed at 69 kVA, A$970, and the bill falls by 48%. Set it lower and the battery runs flat on hot afternoons; set it higher and the charge stays high.
The numbers
Your demand charge is set by the worst half-hour of the month.
A modelled Queensland commercial property using about 470 MWh a year, with 150 kW of rooftop solar and one 125 kW / 261 kWh battery, on Energex's large business demand tariff. We ran it through a hot January: a four-day heatwave, several storm days and everyday forecast errors.
January electricity bill
A$, excluding GSTOptionJanuary billBill per kWh usedPeak demand charge
No solar or batteryA$11,58025.1cA$2,030 (146 kVA)
Solar onlyA$6,760−42%14.7cA$1,620 (117 kVA)
Solar + battery, fixed power limitA$5,980−48%13.0cA$970 (69 kVA)
Solar + battery, time-of-use settingA$5,590−52%12.1cA$970 (70 kVA)
Solar + battery, Tekmor AIA$4,780−59%10.4cA$250 (18 kVA)
Charge in the cheap midday window, discharge from 5pm. On ordinary days this already keeps evening grid demand at zero, and the bill falls by 52%. In the heatwave the battery runs flat around 7:30pm, and that one half-hour sets the demand charge for the whole month: A$970.
Fills the battery in the cheap midday window, sees the hot evening coming and saves its energy for 5–8pm. Peak demand stays at or near zero on most weekdays and holds at 18 kVA (A$250) through the heatwave. The bill falls by 59%.
Peak demand, every weekday in January
Highest half-hour between 5pm and 8pmIn a mild month such as May, a time-of-use setting and Tekmor AI both keep peak demand at or near zero (bill down 53% and 54%); the fixed limit still bills 69 kVA. Simple settings handle the easy days. The demand charge is decided on the hard ones, and that is where Tekmor AI earns its place. Every site is different, so your free assessment models your own load, tariff and roof.
Modelled example, not customer data or a quote. Network charges: Energex tariff 7200, 2026–27 (peak demand A$13.91/kVA/month, weekdays 5–8pm; shoulder demand A$3.67/kVA/month; network energy and daily charges as published). Assumed retail contract: energy 18c peak, 14c shoulder, 9c off-peak per kWh, distribution loss factor 1.05, certificate costs 1.0c/kWh, market fees 0.5c/kWh, retail and metering fees A$2.50/day, export credit 3c/kWh, power factor 0.95. Solar: 6.2 kWh/kWp on a clear January day, less on cloudy days. Battery: 92% round trip, 5% minimum charge. Time-of-use setting: charges from solar and grid 11am–1pm, then discharges to cover the load from 5pm until empty. Fixed power limit: 66 kW all day, recharging from solar or grid while below the limit; this was the best single setting for this site in January. Tekmor AI planned on day-ahead forecasts with 6% load and 15% solar error and re-planned every half-hour. "Bill per kWh used" is the electricity bill divided by total site consumption and excludes the cost of the solar and battery system. Savings shown before Tekmor's software subscription.
Why AI
Same battery. Different result on the day that counts.
The peak demand charge is set by the single worst half-hour of the month, usually on the hottest evening. On 19 January a time-of-use setting runs the battery flat at 7:30pm and the site pulls 66 kW from the grid. Tekmor AI sees the hot evening coming, spreads the same battery across 5–8pm and holds the grid at 17 kW.
The hottest day: 19 January, 37°C
Half-hourlyKnow when the peak will land
The AI forecasts site load and solar output for the day ahead from your site's own data.
Spend energy where it pays
It decides how much charge to hold back, so the battery still has energy when the peak that sets your monthly charge arrives.
Re-plan as the day unfolds
When the day goes differently from the forecast, dispatch is re-planned on live data, within the battery's power and charge limits.
See what your site could save.
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