Photovoltaic glass panels for balustrading systems

Large expansive areas of glass on balustrading, balconies and roof terraces can be a valuable source of solar energy

                                                           
The greatest source of free energy that exists on our earth is the power of the sun. Many countries harness that power and use it to their benefit. Unfortunately, many disregard it and continually burn fossil fuel to heat and light their homes and to power their electrical appliances. Other countries do not have the means or the monetary resources to undertake a capital investment into the technology, for example, many African countries are in this category where the sun shines continually during the day light hours.                                              

Photovoltaic Glass                                                    
Glass is one material that is used throughout the construction of a building whether domestic or business and it can be adapted to harness the power of the sun and produce energy for the building. In this instance we will concentrate on the use of glass in the domestic household where it is used for windows, balustrading and roof terraces on balconies and adapt the glass to enable it to assist in supplying energy to the home.              

This is known a photovoltaic glass which is manufactured in panels and replaces conventional glass whilst simultaneously harnessing energy from daylight. It is very easy to install. The glass is fitted into conventional glazing systems usually without the need for modification of the system.  Electrical connections are made simple and the glazing subcontractor can normally handle inter-connection of the modules.  (Connecting the power to the buildings electricity supply or to the grid should be undertaken by an accredited PV installer).

The initial cost of the solar installation is offset during construction and the electricity produced continues to lower costs during the lifetime of the building. The density of the PV cells can be specified for each individual installation thereby optimising the amount of natural light (or shade) within the building interior. By strategically placing the panels, it will add to the buildings visual appeal, and its multi-functionality meets specifications for light transmission, solar shading, electrical output, and insulation.

The PV cells are crystalline wafers made from semi-conductor grade silicone, and only approximately 200 microns thick, and are available in two standard sizes, 125mm x 125mm (5" square) or 156mm x 156mm (6" square). Spacing between the cells can be varied in both directions however, to meet customer requirements.
The electrical wiring system is designed to fit into traditional glazing systems, and electrical contact is by means of simple plug and socket connectors. The electrical contact busbars can generally be placed horizontally or vertically for optimum aesthetic appeal. Panels can be single glazed or double glazed units which, like ordinary glass, can incorporate low emissivity glass to enhance insulation.

A common misconception – Where there is light there is power                              
It is a common fallacy that PV only works in sunny climates. This is not the case. PV converts light into power and relatively low levels of light are very effective at producing power and south facing glass panels can assist considerable.  Transparent, photovoltaic-glass window can generate 80 to 250 watts of electricity.  This is the next-generation of BIPV (building integrated photovoltaic), an enclosed super-tempered glass window system, fully integrated, multi-tier PV and heat insulation technology.

Some glass manufacturers are also working on embedded smart home technologies, including an optional built-in electrical privacy curtain, to completely block out an already shaded glass window, and a new technology that converts the entire window into a light panel.                            

Use of photovoltaic glass on Balconies and roof terraces

Where better to apply PV (photovoltaic) glass then on balconies or roof terraces?

Most PV installations nowadays are applied as a foreign object or additive to the structure. Using PV glass panels in lieu of regular clear glass for areas already requiring glass is really a natural way forward. Balconies, roof terraces and glass facades all qualify for this.

Glass balconies are built to sit in the sun, roof terrace balustrades many times can take advantage of having the glass exposed on both sides to the sun, doubling it’s output. PV balconies, or balustrades that employ photovoltaic glass are an emerging source of green energy.

Planning, local authorities and building control

Green energy, zero carbon homes and PV all qualify for “gold stars” when dealing or approaching local authorities. Strict government instructions have been given to encourage, reward and help the construction industry, developers and home builders to add green energy to their buildings. Application and use of photovoltaic panels will on most occasions open the door to greater leniency and percentages and in general a positive result on all sides. The government gets a steady progress towards carbon footprint reduction, developers get more square footage and the end user gets a lower electricity bill.

Just recently a project in London was awarded 3 more floors for using PV panels on the balconies, roof and one of the facades.

Unlimited supply of energy

The 89,000 TW of sunlight reaching the Earth's surface is plentiful – almost 6,000 times more than the 15 TW equivalent of average power consumed by humans. Additionally, solar electric generation has the highest power density (global mean of 170 W/m²) among renewable energies.

Pollution free

Solar power is pollution-free during use. Production end-wastes and emissions are manageable using existing pollution controls. End-of-use recycling technologies are under development and policies are being produced that encourage recycling from producers.

PV installations can operate for many years with little maintenance or intervention after their initial set-up, so after the initial capital cost of building any solar power plant, operating costs are extremely low compared to existing power technologies.

An increasing and enticing investment

As of 2011, the price of PV modules per MW has fallen by 60 percent since the summer of 2008, putting solar power for the first time on a competitive footing with the retail price of electricity in a number of sunny countries. There has been fierce competition in the supply chain and further improvements in the levelised cost of energy for solar lie ahead, posing a growing threat to the dominance of fossil fuel generation sources in the next few years.

As time progresses, renewable energy technologies generally get cheaper, while fossil fuels generally get more expensive. The less solar power costs, the more favourably it compares to conventional power, and the more attractive it becomes to utilities and energy users around the globe. Utility-scale solar power can now be delivered at prices well below £61/MWh (0.06pence/kWh) less than most other peak generators, even those running on low-cost natural gas. Lower solar module costs also stimulate demand from consumer markets where the cost of solar compares very favourably to retail electric rates.

Summary

With some of the fossil resources nearing their peak, the sun’s rays are being studied in depth with the intent of making the sun the way forward in producing energy for household and business usage. As older buildings make way for more modern structures where glass occupies a much bigger percentage of the area of a household exterior, using photovoltaic glass is the route that the householder must take to beautify his home and produce his own energy to lower the dependence on the national grid for means of supply power to his household appliances.

On modern homes, one area where large expansive areas of glass are found is on balustrading, balconies and roof terraces. This can be a valuable source of solar energy collection. If a solar energy system is installed in the house a very good investment can be obtained by changing the existing toughened glass to photovoltaic panels.
Local Authorities tend to give precedence and additional planning consent for “green applications” and allow roof terracing with solar energy capabilities to be installed in cases not normally granted. If a planning application is made to add an extra floor to the building it will most likely be approved if it caters for solar energy collection.

Quite often one assumes that because the balcony or terrace is not south facing and therefore gets less direct sunlight it isn’t economical to change this to solar power. The sun’s energy is absorbed from the rays whether direct or indirect, valuable gains can be obtained by changing the existing glass to photovoltaic and installations can make a worthwhile addition to the energy collection system.