AMPROTEQPeaks
A flat load, billed at peak
IT halls run around the clock, so the campus buys as much energy in the peak windows as at night, at several times the price.
Visualisation
Industries · Data centres
Battery storage for data centres.
A data centre buys power every half-hour of the year. Storage takes the campus out of the peak windows, holds its demand under the ceiling and shares the load with the standby sets when the grid goes. The UPS stays as it is.
01 · The problem
What the site
is up against.
Demand
Cooling sets the ceiling
Chillers push demand up in the afternoon heat, and one hot half-hour sets the demand charge for the month.
Growth
New halls need headroom
Each new hall adds one or two megawatts against a notified demand the utility is slow to raise.
02 · What storage does
What the battery
does about it.
- 01Peak shiftingCharges off-peak and at midday, and carries the campus through both peak windows.
- 02Demand ceilingDischarges when the cooling plant pushes demand up, and frees room under the NMD for new IT.
- 03Standby supportShares the load with the standby sets in an outage, so they run lighter and burn less fuel.
- 04Beside the UPSThe UPS keeps its milliseconds. A PULSE transfer cabinet protects critical 400 V boards where they need it.
03 · Typical configuration
Indicative,
before the load study.
| Systems | APEX A5000 blocks (5 MWh, 20 ft) with NEXUS N2500 MV skids |
| Connection | 22 kV on spare MV bays (10–35 kV) |
| Duration | About 2 hours, sized against the peak windows |
| Pairs with | The existing UPS and standby sets; PULSE on critical 400 V boards |
| Commercial model | Purchase; under four years simple payback in the modelled case |
Every configuration is sized from the site's own interval data and tariff; this is a starting point, not a quote.
Part one
Where a data centre’s money goes, and how storage brings it back.
The four-page sector brief, on the page: what a campus pays for in Eskom’s peak windows and on its notified demand, the system we connect at 22 kV beside the UPS, the option that keeps the cooling running through a transfer, and what it returns.
Download the flyer04 · Where the money is
A load that never sleeps,
priced by the half-hour.
The IT load is flat, so a data centre buys as much energy in the peak windows as at night. The battery earns in that gap, and in the demand the cooling plant no longer sets.
The white line is grid draw with a 10 MW / 20 MWh plant: lower through both peak windows, refilled at midday and overnight, never above the 17.4 MW ceiling.
Active energy, transmission zone 0. Plus R62.55/kVA a month on the notified demand and R26.29/kVA a month on the highest chargeable half-hour. A kilowatt-hour moved from off-peak (1.20) into a winter peak (7.20) is worth about five times what it cost, after losses.
Where the battery fitsOur view
| Load | Pattern | Battery role |
|---|---|---|
| IT halls | Flat, 24 / 7, growing | Peak shifting |
| Cooling plant | Afternoon heat | Demand ceiling |
| UPS | Milliseconds to minutes | Stays as it is |
| Standby sets | Hours, on an outage | Run lighter, burn less |
| New halls | Steps of 1 – 2 MW | Room under the NMD |
20.2R mGross saving, year oneAt FY2027/28 prices
34%Less energy bought in peak6.6 GWh moved a year
2MVAOff the notified demandLower the NMD, or fill it with IT
<4yearsSimple paybackOn an indicative turnkey cost
05 · The system
Beside the UPS,
never instead of it.
The UPS keeps doing what it was designed for. The battery works upstream, at 22 kV, on the bill every day and beside the standby sets when the grid goes.
Battery · APEXA5000
Liquid-cooled LFP in one 20 ft high-cube. Four sit on two 22 kV bays in the case study.
- Energy
- 5.0 MWh · 4.5 usable
- DC window
- 1 120 – 1 500 V
- Thermal
- Liquid · ≤ 3 °C cell spread
- Enclosure
- IP55 · C5
- Fire
- Smoke, gas, aerosol
Converters, step-up and MV switching on one skid, matched one-to-one to the A5000.
- Power
- 2.5 MW · 2 DC groups
- Converters
- 12 × 215 kW
- Connection
- 10 – 35 kV
- Grid
- PF −1 … +1 · grid-forming ready
- Grid code
- NRS 097-2-1
One controller runs every job against one state of charge and reports to your BMS.
- Jobs
- Peak · ceiling · PF
- Forecast
- Load and weather
- Protocols
- IEC 61850 / 104
- SCADA
- To your BMS / NOC
- Access
- VPN · on-site HMI
Nothing in the critical path changes: the UPS still holds the IT load through the transfer and the sets still start on every outage. The battery adds a fourth layer that shortens the sets’ work, and on critical 400 V boards PULSE keeps pumps and air handlers turning through the switch.
06 · Option
Keep the cooling running
through the switch.
The UPS carries the IT load through a transfer; the cooling plant usually is not on it. An A2000 behind a PULSE on the mechanical board closes that gap.
01Cooling that keeps moving
PULSE moves the mechanical board to the battery in ≤ 10 ms. Pumps and air handlers keep chilled water and air flowing while the sets start.
02No cold start at the worst moment
The cooling board never drops, so there is no restart sequence while the halls are warming.
03One frame per board
P500, P1000 or P2000 per mechanical board, with one or two A2000 systems behind it at 400 V.
04An option, not in the payback
Added on top of the 22 kV plant where the cooling design calls for it, and priced per board.
07 · The return
An asset that pays for itself
in less than four years.
Figures from the modelled campus on this page, at an indicative turnkey cost. A site proposal replaces them with your own.
<4yearsSimple paybackOn an indicative turnkey cost
39%Project IRR, 15 yearsAfter O&M and augmentation
8.4×The investment, returnedNet cash over the term
Three ways to buy
Purchase Most operators
Turnkey supply, install and commissioning. You own the plant; we run it under a 15-year O&M and availability agreement.
Service agreement
We own and run the plant for a fixed monthly fee, for operators who keep storage off the balance sheet.
Phased
Start with two blocks on one bus section and add pairs as new halls are let and the next bay is free.
Part two
Taking a colocation campus out of the peak.
Illustrative case · composite site · not a client project
The eight-page business case, on the page: a composite 11.6 MW-IT colocation campus in Midrand, modelled half-hour by half-hour for a year on the real 2026/27 Megaflex tariff at 22 kV, then carried over fifteen years.
Download the business case08 · The site
A campus that never
stops drawing.
The modelled campus runs every hour of the year. Its bill is R310 m, and 32 % of the energy cost is bought in 14 % of the hours.
Site profileComposite
| Operation | Colocation, four data halls |
| Region | Midrand, Gauteng |
| Supply | Two 22 kV feeders, Eskom direct |
| Tariff | Megaflex Me02N, zone 0 |
| IT load | 11.6 MW average, filling |
| Annual PUE | 1.32 |
| Notified demand | 20 000 kVA |
| Recorded peak | 19 639 kVA |
| Power factor | 0.95 lagging |
| Standby | 10 × 2 MW sets on the 22 kV bus |
| Annual energy | 134 GWh |
| Annual bill | R310 m ex VAT |
Peak energy costs about as much as all off-peak energy, in a seventh of the hours. It is the line the battery attacks first.
The IT halls set a floor that never moves. Cooling adds the swing, and the swing sets the demand.
Each column is a day from April 2026 to March 2027, each row a half-hour. There are no weekends and no shutdowns: the brighter afternoons are the cooling plant working through the Highveld summer, and the slow brightening across the year is new IT load as the halls fill.
01The brief
Cut the cost of the peak windows without touching the UPS, the tier design or a single customer rack.
02The constraint
Capital is approved on payback. Two spare panels on the 22 kV board, one per bus section, outside the secure perimeter.
03The risk
The recorded peak of 19 639 kVA sits within 2 % of the NMD, and the next hall would push the campus past it.
09 · The load
Flat by design,
swung by the weather.
The IT halls draw the same at 03:00 as at 18:00, so the peak windows carry a full share of the load. The cooling plant adds the swing on top, and it peaks in the summer afternoons.
June to August carry the winter peak price: 44 % of the year’s peak cost sits in those three months.
01The peaks cannot be moved
About 78 % of the peak-window load is customer IT. It cannot be shifted or switched off, only supplied differently.
02Winter costs 2.4 times more
The same kilowatt-hour costs R7.20 in a June peak and R2.99 in a November one, so the value is concentrated in three months.
03Summer sets the demand
Cooling averages 2.2 MW in winter and 3.0 MW the rest of the year. The year’s highest half-hour falls on a hot summer afternoon.
10 · The plant
Four blocks on
two spare bays.
Each 22 kV bus section takes two 2.5 MW / 5 MWh pairs. The plant sits upstream of every hall transformer and UPS, behind the Eskom meter, so the supply agreement and the critical path do not change.
Plant at a glancePer the range datasheets
| Battery | 4 × APEX A5000, 20 MWh LFP |
| Usable | 18 MWh at 90 % depth of discharge |
| Conversion | 4 × NEXUS N2500, 48 × 215 kW |
| Power | 10 MW, 11 MVA maximum |
| Connection | Two 22 kV bays, one per bus |
| Round trip | ≥ 88 % AC–AC |
| Control | Solaris™ EMS, to the BMS by IEC 104 |
| Footprint | ≈ 1 560 m² fenced yard |
Why four blocksFull year at FY2027/28 prices · indicative turnkey cost · NPV at 12 %
| Option | Rating | 22 kV bays | Cycles / yr | Gross saving | Payback | NPV |
|---|---|---|---|---|---|---|
| 2 × A5000 | 5 MW / 10 MWh | 1 | 425 | R11.7 m | 2.8 yrs | R73 m |
| 4 × A5000 ◆ | 10 MW / 20 MWh | 2 | 365 | R21.9 m | 2.8 yrs | R140 m |
| 6 × A5000 | 15 MW / 30 MWh | 3 | 286 | R25.9 m | 3.5 yrs | R145 m |
Two blocks pay back as fast but leave half of each peak on the bill and earn R10 m a year less. Six blocks cannot refill at midday without crossing the 17.4 MW ceiling, so they cycle less and need a third bay. Four blocks fill both bus sections and earn the most per rand. ◆ Selected.
11 · How it runs
Two cycles in winter,
one in the summer heat.
Solaris discharges through both peak windows and recharges at midday without crossing a 17.4 MW ceiling. In summer the chillers leave less room to recharge, so the plant cycles once and guards the ceiling.
Cyan: energy the battery supplies, so the campus does not buy it. Grey: energy bought to recharge, at off-peak or standard prices and never above the ceiling. In January the midday recharge is small, and Solaris spends it holding the line. The lower strip is battery power (±10 MW) and the state of charge. At weekends the battery is held full as reserve.
365Equivalent full cycles a year
6.6GWhDelivered from the battery
1.9per dayWeekday cycles, winter
1.3per dayWeekday cycles, the rest of the year
12 · The bill
R21.9 m a year,
from four lines.
About 90 % of the saving is energy moved out of the peak. The lower notified demand adds the rest, or stays in hand as room for the next hall.
| Value stream | How it is earned | Per year |
|---|---|---|
| Peak energy shifted | Peak kWh bought at off-peak and standard prices, net of 12 % losses | R19.7 m |
| Notified demand | NMD renewed at 18 000 kVA: generation, network and transmission capacity | R1.6 m |
| Power factor | PCS holds 0.99 at the board; the high-season reactive charge falls away | R0.3 m |
| Network demand | Monthly peak in chargeable periods held under the ceiling | R0.2 m |
| Total | R21.9 m |
Bills are rebuilt line by line from the Megaflex schedule (500 V – 66 kV, zone 0): active energy by period and season, legacy, subsidy and ancillary charges, capacity charges on the notified demand, network demand on the monthly chargeable maximum, reactive energy in the high season and daily service charges. The notified-demand saving starts in year two. Keeping the 20 MVA instead leaves about 1.5 MW of new IT load inside it. A wheeled solar contract does not reach the evening peak, so this case holds with or without one. Diesel saved is not counted.
13 · Fifteen years
Less than four years
to pay back. Then it saves.
The operator buys the plant turnkey and we run it. The saving rises with the tariff; O&M and one augmentation block are the only costs after day one.
<4yrsSimple payback
39%Project IRR
140R mNPV at 12 %
8.4×The investment, returned
Even the worst single case leaves an NPV of R111 m.
On the cell maker’s measured curve at 1.0 cycles a day. One more A5000 in year 5 keeps the fleet above 16.2 MWh for the term.
Indicative ownership termsFinal terms in the site proposal
| Structure | Turnkey supply, install and commissioning |
| Ownership | The operator, from commissioning |
| O&M | 15-year service agreement, AMPROTEQ |
| Availability | ≥ 97 %, measured monthly |
| Capacity | Tested yearly; ≥ 16.2 MWh usable |
| Augmentation | One A5000 in year 5, in the plan |
| Monitoring | Solaris, 24 / 7, to the BMS and NOC |
| Alternative | Service agreement: fixed monthly fee |
14 · Resilience & delivery
When the grid goes,
the sets do less.
The UPS and the sets keep their roles. On a published outage Solaris holds the charge, and once the sets have taken the 22 kV bus the battery carries part of the campus beside them.
The battery carries 8.4 MW, 57 % of the campus, and the sets carry 6.2 MW. All ten sets stay on line, as the site’s rules require; each runs lighter. That saves about 4 100 litres of the 10 500 burned with the sets alone (generic set fuel curve). A two-hour curtailment of 3 MW needs no set at all.
Three layers, three jobs
| Layer | Carries | In this plant |
|---|---|---|
| UPS | The IT load, from the first millisecond | Unchanged |
| Standby sets | The whole campus, for as long as there is fuel | Start on every outage, as now |
| APEX + NEXUS | Shares the campus load with the sets; carries curtailment alone | New |
Risks we carry, and how
| Grid-code or protection change | Studies before order; settings agreed with your engineer |
| Work near live halls | Yard and cable outside the secure perimeter; change control |
| Cell ageing | Measured cell data; augmentation in the plan from day one |
Illustrative case on a composite site; not a client project and not an offer. Modelled with Eskom’s Schedule of Standard Prices 2026/27 (Megaflex, 500 V – 66 kV, zone 0) and APEX A5000 / NEXUS N2500 ratings. Tariff escalation beyond 2027/28, the installed cost, the set fuel curve and all site data are assumptions.
15 · Questions
Asked by data-centre
buyers.
Does a battery replace our UPS?
No. The UPS protects the IT load over milliseconds to minutes and stays as it is. The battery plant works upstream at MV: on the bill every day, and beside the standby sets in an outage.
Where does it connect?
Usually on spare 22 kV bays, through NEXUS N2500 skids matched one-to-one to APEX A5000 blocks. Critical 400 V boards can add a PULSE transfer cabinet.
Is arbitrage worth it on a flat load?
Yes, because a flat load buys the full peak. In the modelled colocation campus, a 10 MW / 20 MWh plant takes a third of the peak energy off the bill and frees 2 MVA of notified demand.
Related solutions
How the value
is made.
Peak shiftingShift load out of Eskom Megaflex and Miniflex peak windows.Read more →
NMD reductionUse battery storage to hold demand under your notified maximum demand, avoid excess-demand charges and lower NMD at renewal on large-power-user tariffs..Read more →Backup & islandingKeep critical loads running through load-shedding and network faults.Read more →The data-centre pack.
Two documents,
one decision.
The brief is the four-page case for storage beside the UPS. The case study runs the numbers on a modelled colocation campus, half-hour by half-hour, on the 2026/27 Megaflex tariff.
Sector briefAMP-SB-DC · Rev 1.1
Battery storage for data centres
<4yrsSimple payback
34%Less energy bought in peak
2MVAOff the notified demand
Inside
Download the sector brief
- 01Where the money is
- 02The system: APEX A5000, NEXUS N2500, PULSE, Solaris
- 03Three layers of supply beside the UPS
- 04The return
Case studyAMP-CS-DC · Rev 1.1
Taking a colocation campus out of the peak
Illustrative case · composite site · not a client project
R20.2mOff the bill in year one
39%Project IRR over 15 years
10 MW/ 20 MWhOn two 22 kV bays
Inside
Download the case study
- 01The site
- 02The load
- 03The plant
- 04How it runs
- 05The bill
- 06Fifteen years
- 07Resilience & delivery
Figures in both documents are modelled on Eskom’s 2026/27 schedule and indicative costs. A site proposal replaces every one with numbers from your own data.
Next step
Start with your meter data.
Twelve months of interval data, your tariff schedule and your notified maximum demand are enough for a first sizing and an indicative capex, within five working days, at no cost.