Three times we sold less than we were asked for

Redesigning a Jiaxing building's cooling to fit its energy approval

In 2021 we were preparing Jiaxing Building 2: three halls with 13.5 MW of design IT load. Its energy-conservation review, completed that autumn, approved the project on the basis of a design PUE of 1.25 and a corresponding annual energy allowance. Our original design used water-cooled chillers and would have produced about 1.32 at full load, and worse while partly filled. Built as drawn, the building could have been filled to only about 11 MW before exceeding its allowance, leaving 2.5 MW of constructed capacity we could not sell.

The sales director wanted to open in October 2023 as planned and resolve the energy question later. Our CFO was wary of additional capital. I recommended redesigning the cooling around indirect evaporative units and a higher supply-air temperature, keeping chilled water only for two high-density rows. The redesign added RMB38 million of capital and moved opening to March 2024. A manufacturer that needed 1.8 MW before the end of 2023 placed its contract elsewhere; we estimated that business at about RMB26 million of annual revenue. The founders approved the redesign after I set the stranded-capacity calculation beside the lost contract.

We also had to agree the warmer supply air with customers. Most accepted it after reviewing their equipment specifications. Two asked for cooler rows and pay a supplement reflecting the energy difference. Evaporative units consume water, so we negotiated additional supply with the industrial park's utility and installed metering to report consumption monthly.

In its first six partly filled months the building's PUE was 1.31. In 2025, at 74 per cent of design load, it averaged 1.24, and the remaining capacity can be sold within the approval. The lost contract was a real cost, and the sales team carried it in their year. Next time I would model partial-load efficiency inside the approval submission itself. Our original application described the finished building and said very little about the two years it would spend half empty.

Declining to give up a hall's redundancy for a festival peak

In September 2022 our largest customer, an e-commerce platform operator then responsible for 31 per cent of our revenue, asked for an additional 2.6 MW in Suzhou Hall 4 for seven weeks around the November shopping festival. The hall could supply only 1.1 MW more while keeping one UPS module and one chiller in reserve. The remainder would have meant running the hall without redundancy through the busiest weeks of the customer's year. The temporary load was worth about RMB9.4 million.

Our chief executive was concerned that a refusal would push the customer towards a competitor at its renewal the following year, and the account team proposed accepting the risk because the peak was short. I disagreed. A single chiller failure during those weeks would have affected not only the customer's systems but those of eleven other customers sharing the hall, several of them manufacturers who had chosen it precisely for its redundancy. I recommended offering 1.1 MW in Hall 4 and 1.5 MW in our Kunshan building, connected by a dedicated fibre link, with our engineers helping the customer's team divide its workload.

The customer accepted the Hall 4 capacity, took only 0.6 MW in Kunshan and moved the rest of its peak to a public cloud service. We earned about RMB4.2 million rather than RMB9.4 million. At the 2023 renewal it reduced its committed load by 0.9 MW, and I believe our refusal contributed to that.

The board then adopted two policies: no customer should exceed a quarter of revenue, and hall redundancy may not be traded for temporary load. We have since sold capacity to 46 manufacturers and smaller online retailers, and the largest customer was 24 per cent of revenue in 2025. It remains a valued account. I would now write the redundancy rules into customer contracts well before festival season, so that a refusal reads as published policy rather than as a negotiation the customer has lost.

Moving electrical switching into staffed daytime windows

In April 2019, during overnight UPS maintenance at Suzhou Building 1, a technician from our maintenance contractor opened the wrong output breaker. Sixty-four cabinets lost their B-side supply for eleven minutes. Dual-corded equipment kept running, but seven single-corded devices belonging to four customers stopped, including a server running an auto-parts manufacturer's production execution system. Its lines in Changshu stood still for forty minutes.

Nobody had broken a written rule, because our rules allowed contractors to switch under a verbal brief. As vice-president for operations, I proposed three changes: written method statements signed by the duty manager for every planned switching operation; a second authorised electrician verifying each step; and planned switching only in weekday daytime windows when our engineers and the equipment vendor were present. I also proposed bringing electrical maintenance in house by hiring eighteen authorised electricians.

The objections were reasonable. Several e-commerce customers preferred night windows, when their traffic was lowest. Shift leads pointed out that night maintenance carried allowances some colleagues depended on. The contractor offered a discount to keep the work. Together the changes added about RMB4.1 million a year. The chief executive approved them after we reviewed the incident with the affected manufacturer, whose operations director came to Suzhou in person.

From 2019 to 2025 we completed about 1,900 planned switching operations without a switching error. We also offered single-corded customers automatic transfer switches at cost and installed 212. Nine shift colleagues resigned during the first year, several citing lost allowances, and we later introduced a skills allowance for authorised electricians that restored part of that income.

What I would change is the order. I announced the daytime rule before discussing pay with the shift teams, and some of the resignations followed from that. Our customers were told in advance; my own colleagues should have been told first.