"A heated greenhouse all year round by using flexible residual heat computer servers"

The greenhouse horticulture has an enormous need for heat, and residual heat as a renewable energy source is considered more often. Computer servers generate a lot of heat which is largely left unused. The start-up Block Heating wants to deploy that heat to heat greenhouses. Not by building data centers near greenhouse complexes, but by bringing servers by mobile containers to growers.

The idea for deploying residual heat arose about three years ago. Jeroen Burks, the man behind BlockHeating: "I supplied hardware for data centers and noticed that many customers wanted to make their residual heat useful. Most residual heat is still being routed outside. Together with the customer we tried to find out if we could use residual heat to heat a building. A building of about 400 to 500 square meters is being heated successfully, and the building stays warm even on cold winter days.

Fact is there are few buildings with a large need for heat in the summer, but greenhouse horticulture offered a solution. Jeroen: "If you know how much heat runs through a greenhouse each year, the deployment of residual heat by computer servers is a good match."

Because growers do not want a data center in their greenhouse, Block Heating aims at servers in mobile containers. Jeroen: "A 13-meter container can fit about 800 servers, worth a capacity of one megawatt per year. Depending on isolation and the sort of crop used, the residual heat of only one of those containers can heat a greenhouse of up to 10 hectare all year round."

The focus is on supplying heat through warm water. The heat from the servers can be used to supply water of 60 degrees Celsius. This is considerably lower than residual heat supplied by the industry, but more than sufficient to heat a greenhouse. It is important though to keep the distance between heat source and greenhouse as small as possible. Jeroen: "Another reason why containers are ideal, because the water of 60 degrees can be supplied directly to the growers' buffer tank, which can then be used as desired."

The grower doesn't need to fear having his greenhouse full of servers, or extra tubing and wiring. Jeroen "With minimal adjustments we provide energy saving and an opportunity to makes steps towards growing without gas."

The building of a data center easily has an investment time of five to ten years, but the investment horizon for the deployment of server containers is significantly shorter. We are going to test a version with 80 servers soon, and at the beginning of winter a container with 800 servers should be ready."

In the coming period BlockHeating hopes to get feedback from multiple growers, so the containers can be developed further. "We are fairly selective for the first versions, but interested growers are always welcome."