Solar Power and Key Renewable Energy Solutions for SMEs hotel

Solar Power and Key Renewable Energy Solutions for SMEs hotel

Solar Power

The hotel sector is energy-intensive. Using cleaner and cheaper energy sources will help to reduce operational costs and increase competitiveness and sustainability

An option for many businesses is to source their own energy and in most cases solar power is the only realistic alternative

The sun’s rays (solar radiation) offer a huge potential source of energy that can be used to heat, cool and light buildings. It’s been estimated that more energy from the sun falls on our planet in one hour than is used by in the world in one year.

The three main solar technology systems that convert sunlight into energy are:

Solar water-heating
By far the most commonly used, this solar technology produces hot water. Solar panels collect the energy, which directly heats the water system.

Solar photovoltaics
This converts sunlight into electricity via cells. The technology was discovered by scientists in 1954 and it has been transferred to small devices such as solar calculators and watches.

Passive solar design
New buildings can be designed to collect, store, and distribute solar energy. Features could include south-facing windows and building materials (thermal mass) that absorb and slowly release the sun’s heat.

Saving the planet is all well and good but what return can you expect to make on your green investment?

No matter what solar technology you install, you will start saving on your energy bills immediately and, depending on the system and the prices charged by your local energy provider, you can expect to offset the start-up costs within four to 12 years. Most systems have a 25-year manufacturers’ guarantee and a working life of over 40 years.

Start-up costs alone may put many businesses off but most governments offer grants, interest-free loans and tax rebates to cut the cost dramatically. Businesses can often claim up to 80% of the start-up costs depending on the country.
Disruption to hotels when fitting solar systems is normally minimal, as most work is carried out on roof areas far away from guests and staff.

New-build hotels are able to incorporate all three systems—solar water-heating, solar photovoltaics and passive solar design—to become as self-reliant on electricity as possible no matter where in the world they are located.

Existing hotels have the option of installing solar water heating, solar photovoltaics or both. Solar water-heating is by far the most popular and cheaper option and can produce great savings as well as cut CO_²emissions. Hot water is a constant requirement for any hotel and this system can reduce the need for conventional water heating by as much as two-thirds.

Most of these systems have two main components—a solar collector made up of large solar panels, normally on the roof, and a modified water tank. Systems can be either active or passive. The former is most common and uses an electric pump to circulate the hot water while passive systems rely on gravity and natural thermal currents to circulate the water.

In a solar swimming pool heating system, the existing pool filtration mechanism pumps pool water through the solar collector, and the collected heat is transferred directly to the pool.

Solar photovoltaic systems also use solar cells. There is a huge choice available, including those that are just millimetres thick and can double up as rooftop shingles and tiles, building facades or glazing for skylights.

The traditional solar cells are made from silicon, are usually flat-plate, and are very efficient. Second generation cells are called thin-film because they are manufactured from amorphous silicon or non-silicon materials, such as cadmium telluride. Third-generation technology is made from other materials, including solar inks that use conventional printing press technologies, solar dyes and conductive plastics.

Whatever system is employed, the more panels put in, the more energy will be produced, so space and aesthetics have to be taken into account, but these can be a selling point for the hotel. And most rooftop space is vast.

Paradoxically, solar power can also be used very efficiently in hot climates for cooling. With up to 22% of a hotel’s total electrical expenses going on cooling systems, the potential savings are great. In fact, new techniques are being developed using solar power to run air-conditioning, ventilation systems and dehumidifiers that are just as efficient as standard systems.

Solar air-conditioning works like this. Air is passed over solid desiccants like silica gel or zeolite to draw moisture from the air to allow an efficient evaporative cooling cycle. The desiccant is then regenerated using solar thermal heat energy to dry it out in a cost-effective, continuously repeating cycle.

Solar-powered ventilation works both for heating in the winter and cooling in the summer using a low-energy fan and motor system that can be cost-effectively powered by photovoltaics, with enhanced natural convection exhaust up a solar chimney.

Dehumidifiers are created using an attractive recirculating waterfall that dehumidifies a room using solar thermal energy to regenerate the liquid and a photovoltaics-powered low-rate water pump.

And, of course, you can rig up solar photovoltaic systems to power standard electric-run cooling systems too.
Solar technology is constantly evolving as governments and manufacturers invest large sums of money in research and development.

Solar water heating technology is advancing all the time too. US company Cool Energy is developing a system that produces heat and electricity for the northern hemisphere. It combines a traditional solar water heater with an engine-based generator that operates at 200°C rather than the traditional 500°C.

In cool weather, it provides both hot water and heating while in warmer months, excess heat is used to drive the engine and generate electricity. It can provide 80% of the heating, 100% of the hot water and 60% of a building’s electricity needs.
Solar power has huge potential as a reliable energy source in developing countries, where traditional energy supplies can be unpredictable.

“Key Renewable Energy Solutions for SMEs hotels”, in the Renewable Energy series of the HES project, equipment prices vary between suppliers and between countries, are not always available and need to be updated regularly as they evolve quickly. Installation costs also vary greatly between countries (due, for example, to differences in labour costs). Those costs also depend greatly on whether the installation work entails shutting down the hotel or not.

Generally speaking, other influential factors can be the following:

1.     quality of products and installation;

2.     ease of installation;

3.     geographic and climate conditions (e.g. latitude, number of sunny or windy hours, terrain, hydrological conditions, etc.);

4.     user’s distance from the manufacturer (e.g. in case of purchase of wood pellets or wood chips)

5.     optimal conditions for installations (e.g. good orientation and tilting of collectors in case of solar thermal or photovoltaic panels

One important factor that influences the implementation of renewable technologies in SMEs hotels is the lack of awareness of the prospects these applications offer. Various groups are involved in this process, including:

1. Hoteliers: they certainly play a predominant role in the implementation of RES systems in hotels, particularly in the case of small and medium structures, where the decision-making process is simplified and swifter if compared to larger hotels. Too often, hoteliers do not know which renewable energy technologies are most suitable in their case and what the advantages are after implementation of such systems. Thus, they are unaware that they can save significant amounts of energy – and therefore money –, and do not know they can receive tax incentives from their local, regional or national government – and, again, save money – once the system is implemented and operational.

2. Hotel personnel: once the RES system is in place, many employees in the hotel are not aware of how the system works. A correct “energy behaviour” by employees can definitely contribute to enhancing the hotel’s overall energy performance.

3. Hotel guests: in too many cases, they are not aware of the difference it can make to stay in a hotel equipped with RES technologies, in terms of both energy and CO2 savings (while enjoying the same or even higher level of comfort).

4. Administrators: they are very often not familiar with renewable energy issues; hence they are unable to give the relevant information to the hotelier who would like to apply for the implementation of a RES system

some technical barriers exist which limit RES applications or their optimal performance. Herewith, just a non-exhaustive overview of the most relevant ones per technology:

1.       Biomass (i.e. wood chips and wood pellets): the biomass boiler cannot be connected to a chimney; the hotel building does not have any place to store the wood chips/wood pellets neither in its premises nor in an external storage.

2.       Combined Heat and Power (also known as cogeneration): the hotel building does not have enough space to store a (micro-) cogenerator.

3.       Geothermal energy: the hotel is not well insulated and it cannot dispose of an outside area large enough to locate ground-source heat pumps.

4.       Small-Hydropower: the hotel is not located in the proximity of a river nor the river has a suitable drop in level (i.e. the ‘head’)/flow of water so as to allow hydro turbines to convert water pressure and kinetic energy into mechanical energy, which can be used to drive an electricity generator.

5.       Solar energy (both photovoltaic and solar thermal): some obstacles (such as trees, buildings, or the like) shadow the solar panels; panels face north and are not tilted; the hotel does not have a suitable area where to locate a number of panels necessary to meet the energy hotel needs.

6.     Wind: the hotel is not located in a windy area nor it has a suitable area where to locate the wind turbine.