Page 26 - ISES SWC50

With the development of solar hot water panels in the early 1900’s, buildings could now be heated in the
winter months by using these panels on the roofs and circulating the hot water through the house in radiators
and later underfloor heating. Solar buildings started to adopt the principles of passive solar design and
incorporating solar hot water panels for heating purposes. The highlights provide some early examples of this
from the mid 1900’s.

With the development of commercially available PV in the 1970’s, using solar energy in buildings further
developed by incorporating PV in the building and supplying electrical power to the building. This could occur
with either the solar modules being mounted on the building or being converted into actual building material
such as roof tiles/shingles and wall material.

With the rapid growth of grid connected PV systems from the 1990’s onwards, the number of examples of
the integration of PV with buildings that also incorporate passive solar techniques and possibly solar water
heating is too great to even attempt to document in these highlights. However, ISES has always had a very
close working relationship with the IEA Solar Heating and Cooling (IEA SHC) programme that started in 1977.
To provide the reader with further information, the highlights refer to a number of the IEA publications, in
particular those relating to case studies.

By the 1990’s the term ‘Zero Energy Buildings’ started to be applied, and the highlights provide a snapshot
of some of the Zero Energy Buildings which have been built. The IEA SHC also has numerous case studies
of Zero Energy Buildings. The highlights outline some of the countries which have introduced Zero Energy
Building regulations or similar. Zero Energy Buildings are the future and they are how the world will move
towards 100% renewable energy.

3.6 Solar Energy for the Developing World
In recent years, there has been growing interest in the PV industry and mini-grid markets for providing power
to the unelectrified population in areas of Africa, Asia and other developing countries. However, it is fair to say
that over the last 20 years with the booming grid connect industry, the off-grid market in the developing world
has been overlooked by the majority of the industry. This is reflected in the fact that less than 1% (possibly as
low as 0.1 or 0.2%) of PV modules are used in off grid systems, meanwhile in 2018 789 million people did not
have access to electricity. In 1993, 63% of the modules were installed in off grid systems, and in the 70’s and
90’s the figure varies between the 80 to 100% range at times.

Although a few village systems were trialled in the 80’s, the main systems being supplied were known as
Solar Home Systems (SHS). These were individual household systems comprising a solar module often in the
20 to 50W range, one controller, one battery and a number of fluorescent lights (later compact fluorescent
lights and currently LED). The systems often had the ability to power a radio and small d.c. TV. Solar lanterns
also become very popular as a way of providing lights to the unelectrified.
Despite the simplicity of the systems, there were still quality problems with the products and installation. This
lead to individuals such as Peter Varadi (founder of Solarex) starting the PV Global Approval Program (PV
GAP) to develop product standards, the late Mark Fitzgerald forming Institute for Sustainable Power (ISP) to
develop a program to accredit training programs, and Bernard McNelis etc al to encourage the IEA PVPS to
form Task 9, ‘PV in Developing Countries’ which developed a series of Recommended Practice Guides in the
early 2000’s.

The PV GAP standards became International Electrotechnical Commission (IEC) standards, while the work
carried out by Task 9 is now being done by organisations such as the International Renewable Energy Agency
(IRENA) and under the UN through the Sustainable Energy for All (SE4ALL) program and numerous others.
In addition, the Lighting Africa program which was established in 2009 later expanded to become Lighting
Global, which developed a standard (now IEC standard) for small plug and play solar home system kits. Today
there are plug and play solar home kits ranging up to 350W that are tested and approved through Lighting
Global. With the development of new energy efficient appliances and LED lighting, a 50W system today
can provide the equivalent energy services to a 300-500W system in the 1990’s. These small systems have
become a commercial market, with some companies in Africa selling up to 20,000 systems a month using
micro credit whereby customers make payments via their mobile (cell) phone.

8 | ISES SWC50 - The Century of Solar-Stories and Visions