Solar Roof Energy Is the Answer for Mega Cities of the Future

Seven billion people will live and work in urban areas by 2050 and the demand for energy for all these people will be huge. Local production of energy will be needed with building-integrated photovoltaics (BIPV) key to make cities at least partially self-sufficient with energy. Rapid development in thin-film solar cell efficiency strengthens the business case for BIPV with great opportunities for suppliers of roofing materials and construction companies.

The electricity produced by ‘roof solar energy’ could be used for heating, cooling, running office machinery or even fed back to the grid, earning the building owners money.

The electricity produced by ‘roof solar energy’ could be used for heating, cooling, running office machinery or even fed back to the grid, earning the building owners money.

More than half of the planet’s population lives in urban regions today. This will grow to 75 percent in the next 30 to 35 years. That would mean 7 billion people living in more or less congested areas, all needing shelter, food—and lots of energy.

There is a growing consensus that the mega cities in the future cannot rely entirely on energy produced far away. Besides supply constraints, there are energy losses in the transport of the electricity; logistical nightmares; security issues; and, of course, environmental concerns.

There is a very healthy debate about distributed energy generation, often defined as electricity generation from many small sources. This discussion must be encouraged. We simply cannot solve the energy challenges of tomorrow with energy solutions of yesterday.

The distributed energy discussion has so far mainly centered on local smaller power plants, district energy, more efficient electricity distribution, the ‘smart grid’, etc. That is good. But we must also talk about the potential for local production of renewable energy by the end users on a micro scale, the very individuals who consume all this energy.

What do the end users have in common? Well, they all need a roof over their heads, at home and at work. These roofs can produce renewable energy! So the building industry can play a major role in solving mega cities’ energy challenges.

Building-integrated photovoltaics can be incorporated into the construction of new buildings as a principal or ancillary source of electrical power, and existing buildings may be retrofitted with similar technology.

Building-integrated photovoltaics can be incorporated into the construction of new buildings as a principal or ancillary source of electrical power, and existing buildings may be retrofitted with similar technology.

Look at an aerial image of a city and you will see an area densely covered by buildings—crisscrossed by roads and the occasional recreational area. All these buildings—houses, apartments, garages, offices, factories, schools and municipal buildings of all sorts—have roofs. New development in solar energy has transformed all these roofs—and even walls—into potential giant solar energy receivers.

The electricity produced by ‘roof solar energy’ could be used for heating, cooling, running office machinery or even fed back to the grid, earning the building owners money.

What I call ‘roof energy’ is building-integrated photovoltaics (BIPV), one of the fastest-growing segments of the photovoltaic industry. Photovoltaic materials are used to replace (or are added onto) conventional building materials in not only roofs, but also skylights and facades. They can be incorporated into the construction of new buildings as a principal or ancillary source of electrical power, and existing buildings may be retrofitted with similar technology.

Traditional wafer-based silicon solar cells are efficient but rigid, thick and heavy, ideal for large solar parks in sparsely populated areas but not in dense cities. They are too heavy for most roofs. However, thin-film solar cells made out of a copper-indium-gallium-selenium metal alloy (CIGS) are thin, light and flexible. They can be made frameless, can be bent, and are ideal for buildings and other structures that are uneven, moving or weak.

The business case for thin-film solar cells is strengthening rapidly since they are becoming increasingly efficient. A Swedish supplier of thin-film solar cell manufacturing equipment has managed to increase the aperture efficiency (the area on the solar panel that collects energy) from 6 percent four years ago to 11 percent two years ago and a record breaking 17 percent today by using a revolutionary all-dry, all vacuum process where all layers are deposited by sputtering.

An office, school, storage facility or factory with a flat roof in a Mediterranean country like Italy could annually yield 1,250 kWh from every kW installed, at a production cost of 7.2 U.S. cents. The production cost would decrease if the roof is slanted by up to 20 percent for an optimal 35-degree angle. The production cost would obviously be higher in colder countries and lower in countries nearer the equator. But even in Sweden the production cost could be as low as 8 cents.

Thin-film solar cells made out of a copper-indium-gallium-selenium metal alloy (CIGS) are thin, light and flexible.

Thin-film solar cells made out of a copper-indium-gallium-selenium metal alloy (CIGS) are thin, light and flexible.

A production cost of 5 to 10 cents is well below the current—not to mention the expected future—electricity prices. There are great variations in the price of electricity today, but many users pay between 10 and 30 cents per kWh (including taxes). Commercial and residential users pay even more.

The $100bn global roofing material market is in a healthy state, growing at 3.7 percent per annum and driven by an uptick in residential building construction (especially reroofing) in developed and developing markets. Here is an excellent opportunity for architects, roofing material suppliers and construction companies to take a leading position in what is destined to be the material of choice for urban planners in the future.

Thin-film BIPV solar energy solutions can be made light and are flexible. They can be fitted or retrofitted onto roofs without perforating the roofs and can be curved or bent. Installation is easy and cost-efficient with no racks or ballast needed. There are no weight constraints and no access limitations (you can walk on the panels). And they can be integrated on bitumen and TPO membranes.

Selling roofing solutions and electricity together opens up to completely new business models: suppliers can offer a discounted roofing price in combination with a stable and independent supply of electricity. Customers can secure electricity price—and get a new roof.

Municipalities and city planners in today’s and tomorrow’s mega cities will make efforts to make their cities greener and more sustainable. It is no wild guess that green buildings with ‘roof energy’ systems will get preferential treatment in public tenders and maybe even subsidies. Building owners will like the prospect of lower energy costs.

So the question to the world’s architects, roof manufacturers and construction companies is: Do you feel lucky? Do you feel confident enough to keep doing business as usual, selling traditional roofs to consumers who might sooner than expected demand energy-producing and cost-saving roofs and buildings? Or will you grab an unparalleled opportunity to gain market share by offering state-of-the-art products that will change the world or at least the way the world’s urban population powers their daily lives?

For me, the answer is simple: If end users can produce part of the energy consumed in a sustainable fashion where they live and work, that would go a long way toward solving the energy and climate challenges of the future. Flexible, efficient, thin-film solar cells for buildings are an integral part of this solution.

New Report Forecasts Global BIPV Markets

BIPV Markets Analysis and Forecasts 2014-2021 research report addresses BIPV glass, roofing and siding and assesses the prospects for the competing underlying technologies including thin-film, OPV, DSC and c-Si. It includes forecasts broken out by product, application, technology and region expressed in MW and units.

This latest report “BIPV Markets Analysis and Forecasts 2014-2021” updates quantitative and qualitative assessments and outlooks for the global building integrated photovoltaic market. The publisher of this research has been covering the BIPV market since 2007. This 2014 version of the BIPV market report examines the latest important technological and market developments as well as the various region specific factors shaping the market. While the last few years have been far from robust for the solar market there are reasons for companies and investors to view BIPV with some optimism.

The report addresses BIPV glass, roofing and siding and assesses the prospects for the competing underlying technologies including thin-film, OPV, DSC and c-Si. The research includes forecasts broken out by product, application, technology and region expressed in MW and units. The report also provides commentaries of the various leading key suppliers and industry influencers.

BIPV Glass Markets: 2014 & Beyond industry research report includes a detailed eight-year market forecast with breakouts by type of building and PV technology and in both volume and value terms. This report also discusses how BIPV glass can better be sold to architects, who are sometimes skeptical of the BIPV glass concept, but remain the key decision makers on the demand side. In part this is about improved marketing. But as we discuss in this report, it is also a matter of playing up the aesthetic advantage of solar glass (for example with tinted and colored products) and by incorporating additional smart features such as hybrid light/photovoltaic capability.

CIGS Photovoltaics Markets: 2014 and Beyond industry research report analyzes the opportunities that are emerging for CIGS in the very new phase of the solar industry. The report takes a detailed look into the technical evolution of CIGs fabrication and encapsulation and show how this will impact CIGS market expansion and cost reduction. Much of the report is devoted to the opportunities for CIGS in building-integrated PV (BIPV market) and how CIGS flexible modules and price parity with silicon solar panels could considerably improve the revenues generated by CIGS technology in the near future.

Table of Contents for BIPV Markets Analysis and Forecasts 2014-2021 research report, available for purchase, covers:

    Executive Summary

    E.1 Changes in Market Conditions for BIPV since Our Previous Report

    E.2 Changing PV Material Mix

    E.3 Opportunity Analysis and Roadmap by Type of BIPV Product

    E.4 Opportunities for BIPV in End user Markets

    E.3 Companies to watch in the BIPV Market

    E.4 Opportunity Analysis by Country/Region

    E.5 Summary of Eight-year Forecasts for BIPV

    Chapter One: Forecasting Assumptions and Methodology

    1.1 Background to this Report

    1.2 Objective and Scope of this Report

    1.3 Methodology of this Report

    1.4 Plan of this Report

    Chapter Two: Product segments and emerging trends

    2.1 Emerging Trends in Non-Glass BIPV products

    2.1.1 Roofing Overlay

    2.1.2 Flexible Roofing

    2.1.3 Monolithically integrated Roofing

    2.1.4 Wall attached PV

    2.1.5 BIPV Sliding

    2.1.6 Curtain Walls

    2.2 Emerging Technology Trends and its Impact on BIPV glass

    2.2.1 Roadmap for the evolution of BIPV glass

    2.2.2 Limitations of crystalline silicon for use in BIPV glass and its future

    2.2.3 Current and future use of CIGS in BIPV glass

    2.2.4 Current and future use of CdTe in BIPV glass

    2.2.5 Future of OPV and DSC in BIPV glass

    2.2.5 Encapsulation issues for BIPV glass

    2.3 The aesthetics and architectural merits and de-merits of BIPV glass

    2.4 Key points made in this chapter

    Chapter Three: Key Market Segments and Regional Markets

    3.1 End-user Market Segments

    3.1.1. Zero-Energy Buildings

    3.1.2 Prestige Commercial, Government and Multi-tenant Residential Buildings

    3.1.3 Other Commercial and Government Buildings

    3.1.4 Residential Buildings

    3.1.5 Industrial Buildings

    3.2 Markets by Region and Country: A Discussion of Market Developments and Subsidies

    3.2.1 United States

    3.2.2 Europe

    3.2.3 Japan

    3.2.4 China

    3.3 Key Points Made in this Chapter

    Chapter Four: Eight-Year Forecasts of BIPV Market

    4.1 Forecast of Non-Glass BIPV Roofing Markets (Shipment Volumes, Market Value and Materials Used)

    4.2 Forecast of Non Glass BIPV Wall Markets (Shipment Volumes, Market Value and Materials Used)

    4.3 BIPV Glass (Forecast by Type of PV Technology Used, Area , Revenues, Type of Product)

    4.4 Forecast of BIPV Revenues by Type of Building and Type of BIPV Products Used

    4.5 Forecast of BIPV by Retrofit versus New Construction: By Type of BIPV Product

    4.6 Forecasts by Region: By Type of BIPV Product

    4.7 Forecast of Materials/technology

    4.7.1 Crystalline Silicon BIPV: By Type of BIPV Product

    4.7.2 Thin-Film Silicon BIPV: By Type of BIPV Product

    4.7.3 CdTe BIPV: By Type of BIPV Product

    4.7.4 CIGS BIPV: By Type of BIPV Product

    4.7.5 OPV BIPV: By Type of BIPV Product

    4.7.6 DSC BIPV: By Type of BIPV Product

    4.8 Encapsulation Materials for BIPV Panels

Explore more reports on photovoltaic market (PV) and other reports by NanoMarkets LC.