Cut pump energy costs with solar savings
See exactly how much you can save on electricity for strawberry farming operations in Manchester.
The Facts: What Does It Actually Cost to Run a 45W Pump?
**Full Transparency — Real Electricity Costs** Dillon's Strawberry Farm does not use individual pumps per tower. The entire system is fed by **1 × 1,000W central feed pump**, running **12 hours per day, 7 days per week**. Dillon's Strawberry Farm uses **24W high-efficiency full-spectrum LED lights**, running **6 hours per night only** on the Economy 7 night rate. Natural sunlight provides 10 hours of free light during the day — the only part you pay for is the 6-hour LED supplement on a dimmer that stages throughout the night activated by a light sensor. --- **⚡ System Setup** | Component | Specification | |---|---| | Feed Pump | 1 × 1,000W (runs 12hrs/day, day rate) | | LED Lights | 24W High Efficiency Full Spectrum (runs 6hrs/night only, night rate) | | Lighting Strategy | 10hrs Natural Sunlight (FREE) + 6hrs LED Supplement (PAID) | | Tariff | Economy 7 — Day: 24.5p/kWh \| Night: 13.5p/kWh | --- **⚡ The Facts — 1 × 1,000W Central Feed Pump** Power: 1,000W (1 kW) | Usage: 12 hrs/day × 365 days/year | Rate: 24.5p/kWh (day rate) | Period | Cost (No Solar) | |---|---| | Per day | **£2.94** | | Per week | **£20.58** | | Per month | **£88.20** | | **Per year** | **£1,073.10** | **With solar: £0.** Full saving — every day, every week, every year. --- **💡 LED Grow Lights — Growth Stage Cost Breakdown** LEDs run 6 hours per night only on Economy 7 night rate (13.5p/kWh). Natural sunlight covers 10 hours for free. | Growth Stage | Power Setting | Cost Per Light/Day | Cost Per Light/Year | |---|---|---|---| | Seedling | 50% (12W) | ~0.8p | ~£2.95 | | Growing | 75% (18W) | ~1.2p | ~£4.40 | | Fruiting | 100% (24W) | ~1.6p | ~£5.85 | --- **📊 Total Farm Cost — Feed Pump + 24W LEDs (No Solar)** | Scale | Yearly Cost | |---|---| | 100 Towers | **~£1,100** | | 500 Towers | **~£2,950** | | 1,000 Towers | **~£4,800** | | 5,000 Towers | **~£23,600** | --- **How We Eliminate These Costs** Dillon's uses a **single central 1,000W feed pump** — not one pump per tower. The pump runs on the Economy 7 day rate (24.5p), LED lights run on the cheaper night rate (13.5p), and natural sunlight covers 10 hours every day for free. With a full solar and battery system, both costs reduce to **£0**. **📅 The Scenario** - **Daytime:** 10 hours of FREE Natural Sunlight (Lights OFF) - **Evening/Night:** 6 hours of LED Lights (ON) — this is the only part you pay for **Natural Light Saving:** By using 10 hours of free natural sunlight, we save approximately **£12,000/year** at 5,000-set scale compared to running lights 24/7. **LED Upgrade Saving:** Upgrading from 33W to 24W lights saves **£13,333/year** at 5,000 sets. **Smart Dimming Saving:** Running at 50–75% during seedling and growing stages saves an extra **~£8,000/year** at 5,000 sets. **Total Annual Saving (5,000 setup): ~£33,000**
Optimize grow lights with energy-efficient LEDs
Switch to 24W full-spectrum LEDs, operate them on the Economy 7 night rate, and leverage 10 hours of natural sunlight at zero cost. The outcome is a measurable, scalable reduction in energy expenditure across every level of operation. --- **The Case for 24W Full-Spectrum Technology** Modern LED chips now deliver 3.0–3.2 µmol/J of photosynthetic efficiency, compared to 2.0–2.2 µmol/J from previous-generation technology. A 24W next-generation light produces equivalent usable output to a 33W legacy unit — consuming 30% less electricity in the process. | Spec | Legacy 33W | Current 24W | Saving | |---|---|---|---| | Power per hour | 0.033 kWh | 0.024 kWh | -0.009 kWh | | Daily cost (6hrs, 13.5p night rate) | 2.67p | 1.94p | -0.73p/day | | Annual cost (per unit) | £9.75 | £7.08 | **-£2.67/year** | --- **Annual Energy Savings by Operational Scale (33W vs 24W)** | Quantity | Legacy 33W Annual Cost | Current 24W Annual Cost | Annual Saving | |---|---|---|---| | 100 units | £975 | £708 | **£267** | | 500 units | £4,873 | £3,540 | **£1,333** | | 1,000 units | £9,747 | £7,080 | **£2,667** | | 5,000 units | £48,733 | £35,400 | **£13,333** | --- **Recommended Procurement Specifications** - **Chip:** Samsung LM301H or LM301H EVO — industry-leading efficiency ratings - **Wattage:** 20W–24W actual draw power (not marketing-equivalent wattage) - **Spectrum:** Full spectrum 3000K with 660nm Red — optimised for vertical strawberry cultivation - **Driver:** Mean Well or Inventronics — proven reliability and sustained output efficiency --- **Solar and Battery Infrastructure Requirements** With lighting running solely across a 6-hour night window and pump systems operating on Economy 7, total system demand remains significantly lower than fully artificial lighting configurations. | Scale | Total Load | Solar Capacity | Battery Storage | Space Required | |---|---|---|---|---| | 100 Towers | ~4.3 kW | ~15 kW | ~40 kWh | ~80 m² | | 500 Towers | ~17.5 kW | ~45 kW | ~120 kWh | ~250 m² | | 1,000 Towers | ~34 kW | ~80 kW | ~220 kWh | ~450 m² | | 5,000 Towers | ~166 kW | ~380 kW | ~1,000 kWh | ~2,000 m² | --- **Solar System Investment Overview** | Scale | New Installation | Refurbished / Second-Hand | |---|---|---| | 100 Towers | £25,000 – £32,000 | £12,000 – £16,000 | | 500 Towers | £65,000 – £78,000 | £30,000 – £38,000 | | 1,000 Towers | £110,000 – £130,000 | £50,000 – £65,000 | | 5,000 Towers | £480,000 – £550,000 | £220,000 – £270,000 | --- **Total Annual Operating Costs — Feed Pump and 24W LEDs (Without Solar)** Pump operating on Economy 7 day rate (24.5p) and LEDs on Economy 7 night rate (13.5p, 6 hours nightly at full fruiting stage): | Scale | Pump/Year | LED/Year | **Total Annual Cost** | |---|---|---|---| | 1 set | £1,073 | £5.85 | **~£1,079** | | 100 sets | £1,073 | £585 | **~£1,658** | | 500 sets | £1,073 | £2,925 | **~£3,998** | | 1,000 sets | £1,073 | £5,850 | **~£6,923** | | 5,000 sets | £1,073 | £29,250 | **~£30,323** | **With solar integration: operational energy cost reduces to £0 across all scales.** --- **Annual Savings Summary — 5,000-Unit Configuration** | Saving Category | Annual Saving | |---|---| | Natural daylight utilisation (10 hours, zero cost) | **~£12,000** | | LED technology upgrade (24W vs legacy 33W) | **~£13,000** | | Intelligent stage dimming (seedling and growth phases) | **~£8,000** | | **Total Annual Saving** | **~£33,000** | | **Projected Solar Payback Period** | **1.5 – 2 Years** | 10 hours of natural sunlight at no cost. 6 hours of precision LED lighting at a controlled, optimised rate.
Extra Ideas to Save Even More Money
Six proven strategies to cut your solar investment cost and running expenses further — beyond the standard setup. --- **1. Run Pump on Solar Only (Daytime) — Use Header Tanks / Gravity Feed** Run the 1,000W pump **only when the sun is shining**. Install a header tank (elevated water reservoir) that gravity-feeds the towers throughout the day and night. This means: - Batteries only needed for lights at night — dramatically smaller battery bank required - **Save ~£830/year** on electricity bills instantly (pump cost eliminated) - Smaller solar system needed overall — lower upfront cost - Simpler system with fewer moving parts > This is one of the single most impactful changes you can make to the system design. --- **2. Use DC Pumps Directly — Skip the Inverter Loss** Run the pump **straight from the solar panel voltage** using a DC pump instead of an AC pump with inverter. Benefits: - Saves 15–20% energy waste from inverter conversion loss - DC pumps run directly from panels — no inverter needed for the pump circuit - Lower component cost - Simpler wiring --- **3. Buy Grade B / Ex-Demo Solar Panels** Grade B panels have cosmetic marks only — they work at 95–100% efficiency. Perfect for large farm arrays where appearance doesn't matter. - **Save 30–40% on panel cost** vs new Grade A panels - Same power output in practice - Widely available from UK solar recyclers and repowering projects - Ideal for 1,000–5,000 set configurations where panel cost dominates --- **4. Use Second-Life EV Batteries** Old batteries from Nissan Leaf, Renault Zoe, or Tesla still have **70–80% capacity remaining** when removed from vehicles — more than enough for overnight LED power. - **Cost 50–70% less than new LFP batteries** - Available from UK EV recyclers and battery specialists - Capacity tested and rated before sale - *Note: Requires basic electrical knowledge to connect safely. Consult an electrician.* --- **5. Reflective Liners Inside Towers** Line the inside of towers with **white plastic or Mylar reflective film**. This bounces light back to lower leaves and fruit, improving light distribution without extra electricity. - Allows LEDs to be **dimmed by an extra 10–15%** and maintain the same PAR output - Simple, cheap modification — Mylar film costs pennies per tower - **Save an extra £2,000–£3,000/year** at 5,000 sets by reducing LED intensity --- **6. Split System Design** Run lights and the pump on **separate solar circuits and inverters**: - Lights on one inverter/controller - Pump on a separate solar controller (ideally DC direct — see Idea 2) - If one system breaks, the other keeps running — crop protection maintained - Cheaper to diagnose and fix individual parts - Reduces single point of failure risk --- **Best Combination — Maximum Savings** > **Gravity Tanks + Used EV Batteries + Grade B Panels** | Saving Area | Impact | |---|---| | Gravity tank + daytime pump only | Eliminate pump electricity cost (~£830/yr saved) | | Grade B panels | 30–40% off panel hardware cost | | Second-life EV batteries | 50–70% off battery bank cost | | Reflective liners + dimming | Save £2,000–£3,000/yr on LED costs | | DC pump direct from solar | 15–20% energy efficiency gain | | **Combined result** | **Cut total investment cost by ~50% and running costs near zero** | This combination is the most cost-effective route to a fully solar-powered vertical farm — especially at the 1,000–5,000 tower scale where battery and panel costs are the dominant expense.
What solar saves at scale
See how Dillon's Strawberry farm cuts pump energy costs with solar solutions. Numbers that matter for your farm.
£2.94
Central pump daily cost
1 × 1,000W central feed pump running 12 hrs/day at Economy 7 day rate (24.5p/kWh). Fixed cost regardless of how many towers are fed. Solar reduces this to £0.
£1,073
Annual pump cost (no solar)
The single 1,000W pump costs £1,073.10/year running 12 hrs/day, 7 days/week on Economy 7 day rate (24.5p/kWh). Solar reduces this to £0.
~£23,600
Total farm cost — 5,000 towers (no solar)
5,000 upgraded 24W LEDs running 6hrs/night on Economy 7 night rate (13.5p/kWh) plus the single 1,000W pump. Solar reduces this to £0.
~£33,000
Total annual saving (5,000 setup)
Natural light saving (~£12K) + LED upgrade saving (~£13K) + smart dimming saving (~£8K) = ~£33,000/year at 5,000-set scale. Solar payback: 1.5–2 years.