Solar power

Energy from the sun is the single largest source of energy on Earth. The daily insolation of light from the sun on our globe is approximately 6,000 times the total amount of energy consumed daily on Earth. Solar energy is one of the fastest growing alternative energy sources.

Solar heat pond


Flemming Ulbjerg

Flemming Ulbjerg

Solar Energy Specialist
T: +45 5161 5887
Peter Ritter

Peter Ritter

Head of Department, Decentralized Energy Systems
T: +49 561 2885 7358

Solar heating

Solar heating panels transform the sun's energy into heat or thermal energy by heating up water. Solar heating is one of the most well-known and environmentally sustainable alternatives to traditional energy sources. Ramboll is one of the global leading consultants within solar heating and has been involved in the research and development of the newest technologies, including underground seasonal storage as well as the planning and design of some of the world’s largest plants. Since the cost of solar water heating from large plants is four to six times lower than that of heat from small plants, these large plants are now competitive with some biomass boilers and many electrical heat pump solutions.

Seasonal storage

Large scale solar heating plants has the potential to cover more than 50 % of the yearly heat production. To reach such high heat supply fraction from solar, seasonal thermal storage is needed. Ramboll are currently involved in the design and construction of the worlds two largest seasonal storages reaching sizes of up to 200.000 m3. The energy price from these large systems can compete with natural gas boilers and some electrical heat pump solutions.

The demand for large-scale solar heating plants is expected to grow in countries with warm climates, a centralised heat supply and a progressive climate change policy.


The cost of photovoltaic (PV) systems has dropped significantly in recent years. Now utilities, investors and major electricity consumers have discovered PV in multi MW sizes for their purposes. PV is a reliable, predictable and economic way of generating renewable power. It is the quickest way to set up utility scale power generation, easily extendable and can be installed even in remote regions where access is difficult. Worldwide, more than 200 GW of PV plants are in operation now and the number is increasing fast. Over the last 10 years, Ramboll has provided services for utility scale PV installations in Europe, Africa and the Middle East.

Big and small

Ramboll has provided consultancy services in connection with a number of solar heating plants and PV plants. The plants range in size from 200 m2 to the largest solar heating plant of more than 50,000 m2 and from 500 kWp up to 50 MWp in PV.


Ramboll's consultancy services in this field comprise:

  • Technical and economic feasibility studies
  • Owner's Engineer services and consulting
  • Design, preparation of tender documents and approval by the authorities
  • Construction management
  • Testing and commissioning
  • Follow-up and operation
  • Construction Management and Supervision

More information

Tomorrow's District heating in Denmark

In cooperation with Ramboll, three Danish municipalities in S. Jutland are converting to new flexible district heating solutions. Read more in our brochure.


Sunny countryside

Solar energy project in Lillestrøm

State-of-the-art renewable energy project

Solar heating plant and pit storage in Vojens, Denmark

South-Jutland stores the sun’s heat in the world's largest pit heat storage

In the Danish town of Vojens, a 70,000 m2 solar heating plant is being established. The heat is absorbed to heat water, which is then transported to a 200 million litre pit, for storage. Here, the water is saved for district heating consumers to use during the autumn and winter season. Vojens District Heating and Ramboll have designed and constructed the record breaking project.

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