Green Solar Cities

Peder Vejsig Pedersen, Jakob Klint, Karin Kappel, Katrine Vejsig Pedersen

• Publisher: Routledge
• Year: 2015
• Print ISBN: 9781138468740
• eBook ISBN: 9781317673422
• Topic: Biological Sciences
• Subtopic: Ecology
• Index: Biological Sciences

The Green Solar Cities, EU-Concerto project focuses on the practical large scale implementation of solar energy technologies in combination with new build and retrofit low energy building in the cities of Copenhagen, with its city part Valby, in Denmark and Salzburg in Austria. This book aims to influence decision makers in European cities towards a similar approach to the Green Solar Cities project, in close cooperation with leading building component suppliers, energy companies and engaged builders also working with local city officials.

This book will benefit those in a situation where many cities aim at a "Smart City" development, but without clear policies of how to achieve that in practice. In Denmark there are similar policies, with an overall aim to be CO2 neutral by year 2025 in the city of Copenhagen. However, there is still a lack of understanding concerning, how solar energy as the world's number one energy source can play a major role here and how this can be combined with energy efficiency policies, use of district heating and combined heat and power.

The general aim is to introduce the international "Active House" standard and work on "Active Roofs" of the future. The connection between solar energy and low energy building and energy renovation is aimed to be ensured by help of the "Active House" standard which has been developed in cooperation with a number of leading building component manufacturers in Europe.

Chapter 1

Solar Energy in Cities

PEDER VEJSIG PEDERSEN AND JAKOB KLINT

Green Solar Cities: EU Concerto project

With the improved demands in the EU Building Directive from 2010 aiming at a nearly zero-energy standard for new public buildings by 2018 and all buildings by 2020, and with a demand towards the EU member states to create a similar standard for existing buildings, the challenge is to create a whole new basis of energy-efficient building design in Europe. At the same time the City of Copenhagen has an ambition to become the first carbon-neutral capital by 2025.

Extensive retrofitting of buildings, reorganisation of the energy supply and change in transport habits are some of many initiatives the City of Copenhagen will implement in order to become carbon neutral. With the Copenhagen Climate Plan the Danish capital combines growth, development and higher quality of life with a reduction in carbon emissions of around 1.16 million tons.

In the EU Concerto project, Green Solar Cities (2007–2013) (w­w­w­.g­r­e­e­n­s­o­l­a­r­c­i­t­i­e­s­.c­o­m­) EU funding has been utilised as a strong support for the large-scale PV implementation plan in the Valby part of Copenhagen. It was launched in 2000 and aimed at supplying 15 per cent of all electricity use in Valby using 30MWp of PV electricity by 2025. By 2013 around 4MWp of PV has been established, but only 600m² of solar thermal installations. If this increased to 54,000m² of solar thermal capacity, a true 1:1 solar energy combined heat and power solution will be available to document an optimised combination to the large-scale combined heat and power system in Copenhagen. This will actually utilise biomass in the future in the form of wood pills.

At the same time a number of new-build and housing renovation projects have improved their energy frame values by 30–79 per cent compared to normal practice.

Figures 1.1 and 1.2 show a gable with solar art directed towards the railway in Valby (by artist Anita Jørgensen). Here, PV is supplying electricity for neon light, which illuminates at night and is a landmark for the Valby PV plan.

In the Green Solar Cities EU Concerto project there is cooperation between the city of Salzburg in Austria and the local energy agency SIR. A so-called micro grid with district heating has been combined with 2000m² of solar thermal solar collectors and a buffer tank in combination with a heat pump (Figures 1.3–1.5).

1.1
PV art at ‘Prøvehallen’ gable in Valby, which can be seen from the railway, is a symbol of the Valby PV plan. Photo: Anders Sune Berg.

1.2
The PV gable in daylight. Photo: Anders Sune Berg.

The idea is to introduce elements from the so-called ‘Active House’ concept (see w­w­w­.a­c­t­i­v­e­h­o­u­s­e­.i­n­f­o­) in relation to the Green Solar Cities project evaluation in Valby. A number of specifications are defined within the areas of energy, indoor climate and environment. Within energy focus is on energy balance, energy design, energy supply, energy monitoring and verification and follow-up. Energy balance is based on a calculation of all energy uses in a building, including electricity-using appliances and the energy supply system.

The Active House specification demands a procedure for energy monitoring, verification and follow-up. At present in Denmark focus is only on good calculation procedures, but there is no link between the calculations and the actual energy use in the building. This presents a good reason to introduce the same demands for ‘verification’ of all new-building projects within a two-year period, which has already been introduced in Sweden.

1.3
Buffer tank for solar thermal energy in the Lehen area of Salzburg.

1.4
New-build with solar collectors in Lehen, Salzburg.

1.5
Solar collectors and a buffer tank are part of a low-temperature micro grid. Photo: SIR (w­w­w­.s­i­r­.a­t­)

The 777kWp (kilowatt-peak) PV installation at Damhusåen Waste Water Treatment Plant in Valby (Figure 1.8) cover an area of approximately 14,000m² of secured landfill with a built-in liner below the grass. This land cannot be used for anything for many years due to pollution from residues of waste water. This example has huge prospects since waste water treatment plants represent 8 per cent of all electricity use in Denmark

1.6
Active House specifications.

1.7
The director of the ‘Lynette Cooperative’ Torben Knudsen was a driving force of the plan to realise the Damhusåen PV plant, here also supporting the large-scale PV plant for Valby.

1.8
Photo of the Damhusåen PV plant in Valby, which by January 2013 was the largest PV plant in the Nordic countries. It covers 8 per cent of the electricity at the Damhusåen waste water treatment plant, which is owned by the ‘Lynette Cooperative’ in Copenhagen (now Biofos). It is supplementing biogas-based electricity production to cover almost 50 per cent of yearly electricity use by renewables.

1.9
Photo from a large housing retrofit project in Valby at Hornemannsvænge housing estate: 14kWp of PV (100m²) and 100m² of solar thermal is used for each of six renovated housing blocks.

At the Hornemannsvænge housing estate, low-energy retrofit solutions are used together with solar energy combined heat and power...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Preface
• Introduction
• 1 Solar Energy in Cities
• 2 Solar City Copenhagen
• 3 Green Solar Cities
• 4 Energy-Efficient Buildings
• 5 Visions
• 6 Smart Solar Cities
• Photographer list
• Bibliography
• Index