The Ivy League University in New Hampshire is replacing the old fuel-oil fired CHP plant with a 100% renewable biomass system, making Dartmouth one of the most eco-friendly universities amongst the Ivy League campuses.
Founded back in 1769, Dartmouth is along in years. And so is the university’s energy supply, which will now be replaced with a new highly efficient and eco-friendly system.
Two different energy systems are being explored as potential replacements for the old steam system, and once the faculty make a final decision, approximately 6300 students and 3000 employees will benefit from an improved indoor climate.
Biomass based solutions
Both potential solutions are biomass based; one is a heat only and the other is a combined heat and power plant with a ORC (organic ranking cycle). Ramboll is responsible for concept plans and basic design, and if the money is grated the new energy supply is expected to be ready for use within 2-3 years.
The campus area covers 128.97 km2 and consists of 120 buildings with a peak winter heat load of 30 MWt. The biomass driven CHP plant solution shall assist in covering this peak and will be fuelled primarily with locally-sourced wood chips. The anticipated annual woodchip consumption is approx. 50,000 tons. The ORC technology has formerly been used successfully in the industry sector, but it is the first time that it will be applied to a university.
Improved indoor climate and fewer repairs on campus
The main cost of the project is the renovation of old campus buildings in order to make them fit for the new energy supply. In the long run, this cost will be outweighed by the general efficiency of the new system.
Besides being an economically sound investment, the new energy supply also saves the environment a considerable amount of CO2 and improves the indoor climate at all campus facilities.
Another benefit is that the conversion will put a stop to the constant repair work and digging up of old, wrecked steam lines which has become a frequent occurrence in the campus area.
Ramboll’s role: Planning and technical issues
The main deliverables consisted of two concept design reports covering planning and technical issues associated with the network and plant design, including piping/equipment selection, network installation/construction considerations and conversion of the existing buildings internal systems from steam to hot water.
Following this preliminary study, Ramboll continued to work with the College on the next phase of the project. It was the intention of this phase to further optimize the energy supply solution for the production of heat and electricity, hence a feasibility/option appraisal study was carried out for four alternative scenarios:
- ORC Biomass
- Biomass heat only
- Biomass + solar + storage
- ATES (aquifer thermal energy storage) / Heat Pump for heating and cooling
A basic design and cost appraisal for the two best scenarios was then conducted.