INTRODUCTION
Zhouzhuang Wyndham Grand Plaza is a Chinese five-star luxury hotel, located in Zhouzhuang, a famous tourist resort. Its total area is 34,022 m2.
According to a Chinese star hotel report, the average annual electricity consumption of a Chinese star hotel ranges from 100kwh/m2 to 200kwh/m2, ten times as the consumption of a common household. Compared to the population mean, our target hotel consumed about 130.34kwh/m2, which is a comparatively large consumption. The reason why we disregard other resources consumption, like water consumption, is that this hotel has installed facilities as their infrastructures for water use efficiency. The reason why the ballroom (which is mainly for accepting customers, holding banquets and arranging meeting and other versatile functions) is our target objective is that the ballroom has a high utilization rate compared with such like bedrooms and entertainment areas etc. Another reason is that the ballroom takes up the largest space among the single area in the hotel and the solar panels are going to be installed on the roof of the ballroom. As the electricity consumption varies from season to season in that during summers and winters, the peaks of consumption will occur, especially in the summer because the AC systems, including all refrigerating facilities, keep working for 24 hours. Meanwhile, considering different alternatives that may be used as the energy resource for the hotel, solar panels are suggested after these factors have been taken into consideration that the high utilization rate of the solar panel, no transportation fees for resources supply, low installation cost and last but not the lease, the efficiency and durability of both facilities and energy. These panels can also be utilized without putting them in idle without electricity consumption after using for a while since the solar panels have the ability of storing the electricity generated by them. Besides, the most important point is that solar energy is clean energy which means no waste generated during energy transformation and usage, and to a large extent, they can save the hotel a promising number of cost of utilization. As a profit-driven organization, it is common to compare the difference in terms of cost, quality, and capacity of every type of a solar panel. Therefore, this paper will start from the current situation, the solar panel marketing research, production description and the comparison analysis of solar panels and that is the core part of this paper and finally, the recommendations.
PROBLEMS
Currently, except for facilities of electricity consumption, the hotel has invested more or less in energy and cost saving ones. Besides, referring to the volume of electricity consumption of various items, the air conditionings (AC systems) take up the largest proportion, 47% of the total consumption, following the lighting systems and other systems, including the elevators and appliances, and the electricity consumption of the first two are consistent, therefore, the greatest potential of energy saving or sustainability results from air conditioning and lighting systems. The ballroom consists of two meeting rooms, a big reception area, kitchen and other place for stuff and restrooms, so the total net area is about 2455m2. Based on the annual electricity consumption in 2010, which is about 130.34kwh/m2, the total consumption of the whole ballroom is 319,984.7kwh. In addition, the consumption of AC systems and lighting systems respectively are 54.14kwh/m2 and 26.82kwh/m2, which will result in 132,913.7kwh for AC systems consumption and 65,843.1kwh and for the rest of the items, their consumption are summed as about 49.38kwh/m2 and lead to 121,227.9kwh.
One the other hand, the hotel uses water circulation to provide heat and for cooling functions. To some extent, it can save energy, however, this circulation also needs electricity to operate and this type of consumption is included in other consumption instead of air conditioning and lighting systems. In other words, if methods are found to save the consumption of electricity, not only the hotel can save quite a large amount of costs, but a great contribution will be made to the environmental protection.
ALTERNATIVE ANALYSIS
Solar Panel Market Research * Global Energy Consumption
According to the graph, Global primary energy consumption decreased by 1.1% in 2009. However, Renewable forms of energy were the only increases. Despite the 2009 declines, world consumption of marketed energy from all fuel sources is expected to increase over the next 25 years.
Figure1: World Marketed Energy Use by Fuel Type (quadrillion Btu)
* Demand for Renewable Energy Sources
Renewable energy sources accounted for 19% of global energy demand in 2008. Traditional biomass is the bulk of that demand and Hydropower is in the second position with a market share of 3.2%. Solar panel accompanied by Biomass, geothermal hot water and heating is accounted for 1.4% of the energy consumption.
Figure2: Renewable Energy Share of Global Final Energy Consumption, 2008
* Global Electricity Generation and Capacity
From 2003 to 2008, the fast increase in world energy costs combined with concerns about the environmental consequences of greenhouse gas emissions, has led to interest in alternatives to fossil fuels, particularly nuclear power and renewable resources. Government incentives as well as higher fossil fuel prices persuade to improve the future of generation from solar energy along with other renewable energy sources.
Figure4: World Renewable Electricity Generation by Energy Source, Excluding Wind and Hydropower (billion kilowatt-hours)
Solar Panel Cost
The cost of solar panel is variable and actually depends on the time, place and scale of the solar panel installation. Over the long term, there is clearly a systematic reduction in the price of cells and modules. For example, it was estimated that the quantity cost per watt was about $0.60 in 2012, which was 250 times lower than the cost in 1970 of $150.
The great reduction in solar panels cost has been driven primarily by the improvements in the manufacturing of solar panels. In order to facilitate penetration of solar panel installations in the production of green energy, governments have given various incentives to make solar energy more affordable and attractive as well as stimulate demand for solar panels. Solar energy companies have acknowledged both the need towards green solar energy and the opportunity to explore both solar energy and financial incentives in a fast growing market. Therefore, solar energy companies compete in a very competitive environment (national and global) driving the significant drop in solar panels cost.
Advantages of solar Energy
1) Infinite Free Energy: Nationwide indicated that electricity rates have been increasing 6% per year over the last thirty years. The amount of available solar energy is roughly 10,000 times that currently required by humans and it’s constantly replaced. 0.02% of sunlight (if captured correctly) would be sufficient to replace every other fuel source currently used. In addition, when you go solar, you could control your electricity costs.
2) Help the Environment: The electricity that most of us use made from dirty fossil fuels. Burning of them releases toxic emissions. They contribute to smog and acid rain. Electricity is the leading man made contributor to global warming. On the other hand, solar energy is non-polluting, clean, reliable and renewable source of electricity. It does not pollute the air by releasing harmful gases.
3) Decentralization of power: Solar energy offers decentralization in most (sunny) locations (self-reliant societies). Oil, coal, and gas used to produce conventional electricity are often transported cross-country or internationally. This transportation causes additional costs.
4) Going off the grid: Solar energy can be produced on or off the grid. The ability to produce electricity off the grid is a major advantage of solar energy for people who live in isolated and rural areas. Costs of power and its installation are often extremely high in these places and many have frequent power-cuts.
5) Solar jobs: Solar power provides green jobs. Production of solar panels for domestic use is becoming a source of employment in research, manufacture, sales and installation.
6) Low maintenance: Solar cells generally don’t require any maintenance and run for long time. More solar panels can be added from time to time when needed.
7) Easy Installation: Solar panels are easily installed and any wires, cords or power sources are not required. Unlike wind and geothermal power stations, solar panels do not require to be tied with drilling machines, and they can be installed on the rooftops and no new space is required.
Disadvantages of Solar Energy
1) Non constant energy: solar energy production is not constant. There must be sunlight in order to produce solar electricity. Beyond daily fluctuations, solar production decreases over winter months when there are less sunlight hours and sun radiation is less intense. So energy must be stored or sourced elsewhere.
2) Solar Inefficiency: Solar energy production is relatively inefficient. Currently, widespread solar panel efficiency (how much of the sun’s energy a solar panel can convert into electrical energy) is at around 22%. It means that a vast amount of surface area is required to produce a lot of electricity. However, efficiency has developed dramatically over the last five years, and solar panel efficiency should continue to rise steadily over the next years.
3) High cost (One of the biggest disadvantages of solar energy): The main obstacle for developing solar energy is the cost of installing solar panels. Capital costs for installing a home solar system or building a solar farm are high. Installing solar panels has great upfront costs. After which the energy consumes for free.
The countries which produce solar energy * China
As of 2010, the world leader in the use of photovoltaic panels is already China which also produces 55 percent of the world's solar thermal technology (used to heat homes and commercial buildings throughout China's biggest cities), according to the Worldwatch Institute. China has set a goal to derive 10 percent of all energy from renewable sources by the year 2020. A large portion of these sources will include electricity from photovoltaic panels as well as solar water heating technology. * Japan
Japan produces about 45 percent of the world's solar energy, and exports as much as 30 percent of this energy to other countries. While large commercial solar plants produce much of this solar production, Japan also encourages solar energy use for private residences. According to the University of Michigan, in terms of the number of home solar systems, Japan is the world leader. * U.S.A.
The U.S. generates roughly 27 percent of all solar energy used in the world, according to Evergreen University. A series of tax credits and incentives at the federal and state levels encourage the increased residential use of solar technology. 2012 was a historic and busy year for the U.S. solar market. Photovoltaic (PV) installations grew 76% over 2011, to total 3,313 megawatts (MW) in 2012, with an estimated market value of $11.5 billion. Each market segment (residential, non-residential, and utility) showed growth over 2011, while the overall marketsin most U.S. states expanded as well. * Germany
Despite the frequent clouds and lack of sunlight in Germany, this country is at the cutting edge of solar technology. 15 of the 20 largest solar power plants in the world are located in Germany, and it continues to invest in new solar technology. Germany has set a nationwide goal of 25 percent renewable energy by 2020. * Developing Countries
Perhaps the greatest potential for solar energy use lies in developing countries. According to Middle Tennessee State University, solar heating and electricity can be found in many remote regions of Indonesia, Kenya and the Philippines. In countries with few traditional utility companies, connection to a main power grid is impossible for large numbers of people. Therefore, solar technology represents an opportunity to supply light and heat for education and healthcare in distant regions.
Solar Panel Selection
Before choosing any solar panel kits, it is better to determine its function first. For example, Will it be used as a major power source or will it just be used to power up a few appliances in the house? Also, does the house have enough space to place the solar panels? In this case, solar panels have been decided as the major power source of the ballroom, also the area of the ballroom is already know, the next step is to calculate the cost of purchase.
Solar panels cost anywhere from under a hundred dollars to thousands. When selecting the best solar panels to install for solar power system, there are a number of factors worth considering. The cost of a solar panel is determined in part by the size (in Watts), the physical size, the brand, quality of materials, the durability / longevity (or warranty period) and any certifications the solar panel might have. Choosing a solar panel on price alone is not wise, as it may not fit the area you wish to install it, may not have the necessary certifications to qualify for government rebates, provide the best performance to help ensure economic payback of the power produced, or a solid warranty. * Tolerance
This is the range a panel will either exceed or not meet its rated power. For example, a solar module may have ‘nameplate’ wattage of 200 watts; but due to quality control issues, may in reality only be 195 watts. A positive tolerance rating means the panel will not only generate 200 watts, but perhaps more under standard testing conditions. * Temperature co-efficient
The temperature co-efficient rating is important to determine what the impact heat has on a solar panel’s operation after installation. The lower the percentage per degree Celsius, the better. * Conversion efficiency
The efficiency of how a solar panel converts light into electrical energy will determine how much power your system generates. * Embodied energy
Another important aspect to look at is the embodied energy of the solar panel – that is how energy intensive the production of the panel was and how quickly it will have paid itself back by producing more energy. * Size and Watts
The size of the solar panel in Watts will directly affect the cost, as solar panels are usually priced (and compared) in dollars per Watt. Watts are related to the output of each panel; meaning a 100Watt panel under ideal conditions will generate 100 Watts of electricity each hour and a 200 Watt panel will generate 200 Watts each hour. Therefore expect to pay double the price for the 200 Watt panel, compared to the cost of a 100 Watt panel. The output of a panel also affects the physical size of the panel, meaning the 200Watt panel will be larger in size to the 100 Watt panel. . The type of solar cells used in its production also determines the size of the solar panel. The key issue to consider is that your system sizing is enough to power your appliances, and that the solar panels will physically fit in the area you wish to install them. * Types of solar cells used
There are 3 main types of solar cells and the best solar cells will vary depending on the installation application. First, Mon crystalline solar modules are the most expensive and there is a reason for this. These modules are made from a single large silicon crystal. Typically, a mono crystalline module will begin producing electricity at about 5% of maximum sun energy while a polycrystalline module will start producing power at about 10% maximum sun energy. This means that the mono crystalline module will produce energy for more hours per day and in lower light conditions. Additionally, the mono crystalline module will perform better and produce more energy in hot conditions. Second, Polycrystalline solar modules are made by taking raw silicon and forming it into an ingot. This ingot is sliced into cells. Polycrystalline cells typically are less efficient than mono crystalline as they require slightly more light to start up and they output less energy at higher temperatures. Typical Polycrystalline modules are the Sharp 208, 216 and 224. Third, Sanyo Hybrid modules incorporate the best of both worlds. Sanyo modules have a mono crystalline core with amorphous silicon deposited on the top and bottom. The Sanyo HIT modules will start up in very low light, thereby outperforming polycrystalline, will perform 10% better at high temperatures due to the very low temperature coefficients and have the highest efficiency (watts per square foot) available.
Consider all the factors, the four following products are selected to make a comparison: | Price | Cell Type | Performance(years) | Temperature Performance | Mechanical Specifications | Solar World Sun module 235W Mono | $699 | Mono crystalline | 90% of nameplate rated power | 49 °C | 46.7 lbs (21.2kg)1.68m2 | Sanyo HIT-N235SE10 Solar Panels | $519 | hybrid cells (Mono+Poly) | 93% of nameplate rated power | 48.3°C | 2.56 (m2)33.1 Lbs. (15kg) | 237W solar panels BP Solar BP3237T poly | $356 | Polycrystalline | 87% of nameplate rated power | 45 °C | 1.67 (m2)45 lbs | Solar Panels 235W eco Solargy Orion ECO235S156P | $209 | Polycrystalline | 78% of nameplate rated power | 46 °C | 1.61(m2) 42.55 lbs (19.3kg) |
The chart shows that there is a sort of straight line relationship between the price and the type of cell. Mono crystalline is definitely the most expensive cell, while it performs better under high temperature. However, Sanyo HIT-N235SE10 Solar Panels performs better compare with the nameplate 235w, than other products. Since the price already include the cost of tax and the cost of installation, the size of each panel will determine the total purchase cost, and the percentage of installation fee in total price. Except Sanyo HIT, other four products are at approximated 1.65sqm2 per unit, while it is the lightest product that means, the percentage of installation fee of Sanyo HIT is the least.
Solar Panel Comparison Analysis
At first glance, there isn’t even a standard DC watt rating. 200, 210, 220 etc. seems obvious, but then there’s 205, 208, 216, 225. What does all this mean?! It simply means that the panels produce at slightly different outputs. It is necessary to standardize the comparison by including “Cost per Watt” and “PTC Watts per Sqft” (aka Density). In this case, we target at 235w capacity products and standardized the unit by kWh and Sqm2. I’ve also included “True” factors, which simply means numbers based in reality as opposed to theory. Though a panel may have high efficiency, consumers can’t use 5.65 panels; they have to put 5 or 6 panels on your roof. And the sqm of 6 panels is going to be more than that of 5.65 panels. | QuantityRequired | OutputPower(Annual) | Deviation(10 years) | PurchaseCost | Solar World Sun module 235W Mono | 1461 | 4,436,322.5 kwh | 7% | $1,021,239 | Sanyo HIT-N235SE10 Solar Panels | 989 | 4,584,199.9 kwh | 10% | $513,291 | 235W solar panels BP Solar BP3235T poly | 1470 | 4,288,445.1 kwh | 18% | $523,320 | Solar Panels 235W eco Solargy Orion ECO235S156P | 1524 | 3,844,812.8 kwh | 18% | $318,516 |
The two most important numbers in comparing solar PV systems are 1) the AC kWh output/year, and 2) the cost. Whichever complete system can give the most yearly output at the best price is the system to choose. The AC kwh output/year equals the actual output times the time of a year divided by one thousand. To calculate the quantity of solar panel required, the author use the area of the roof of the ballroom, which is 2455Sqms, divided by the size of each panels. Meanwhile, Many of today’s lower quality products can deviate by as much as 15% from panel-to-panel and still be within their stated specifications. This deviation, which is found even with some brand-name solar panel manufactures, comes from buying low quality solar cells suppliers. Negative deviation comes right from your bottom line in the form of higher utility bills. From the chart, the Solar World’s deviation rate the lowest due to it’s mono crystalline cell module, yet the hotel has to purchase 1461 pieces of Solar Word panels to achieve an 4,436,322.5 kwh annual output in expense of $1,021,239. The lowest purchase cost come from 235W eco Solargy Orion ECO235S156P due to its cheap price, but the performance rate is only 78% of nameplate output rate and it will deviate up to 18% in ten years, the low performance rate and the high deviation rate will finally increase the cost of maintain fees, thus author do not suggest the eco Solargy Orion ECO235S156P.
The Cost Analysis of Current Situation
For the current situation, variable cost is mainly the electricity fee. The overhead and administration costs are allocated into the fixed cost as the hotel pays these costs every half year. After considering all the possible fixed costs and doing several calculations, our group come up with an approximate number of the fixed cost: 5,000,000 yuan in Chinese currency. For the variable cost, as the electricity is the only variable, the unit cost of it is: 0.882 yuan per kwh. According to the price policy of the hotel, it will charge 20% premium on the electricity consumption of each customer and through policy, the unit selling price is 0.882 × (1 + 20%) = 1.0584 yuan without adding the factors such as other related costs because this 20% has included all the possible causality of the variable cost. The major point of calculating these costs is for approaching the break even point, which will show the total electricity the hotel needs to consume to cover the fixed cost in order to make better decision for making profits.
As the break even point goes: fixed cost / unit CM, in addition, the unit CM = unit selling price – unit variable cost, which is 1.0584 – 0.882 = 0.1764 yuan, the result of the break even point is 5,000,000 / 0.1764 = 28,344,617.20 kwh. This result means, as explained above, that the hotel needs to consumes more than 28 million kwh electricity and for your information, one metric ton of standard coal can generate 3000 kwh, so it is a huge consumption of both coal and electricity and besides, that consumption will cause a noticeable hazard to the environment and large costs. Something should be initiated to change this situation.
The Cost Analysis after the Installation of Solar Panels
The hotel wants to save costs and spend as little as it can to change this situation. However, the cost of solar panels installed on the roof of the ballroom will be 3,182,404 yuan, which is almost the total cost of the original fixed cost. How expensive! Beware. Don’t jump to the conclusion so quickly. After selected, this brand of solar panel can generate 5,053,863 kwh annually (here is the formulation: 235 × 2455 / 1000 × 24 × 365). So what? The annual electricity consumption of the ballroom is just 319,984.7 kwh (here is the formulation: 130.34 × 2455). Now the difference is obvious: the electricity generated by the solar panels totally covers the consumption by the ballroom and there is even excessive electricity. This is very important to this hotel management when decisions are made. Since there is no longer demand of the electricity from the power plant, the variable cost is zero. Amazing!! Here comes the break even point again. According to the formulation, the fixed cost will change from 5,000,000 to 5,000,000 + 3,182,404, which equals to 8,182,404 yuan. New unit CM will be only 0.882 ×（1 + 20%）, which equals to 1.0584 yuan. Now the new break even point is 8,182,404 / 1.0584, which equals to 7,730,918.56 kwh. The hotel only needs to consume less than 8 million kwh to cover its all fixed cost. What is more amazing is that the new break even point is much less than the current one. A great and distinguished contribution to the environmental protection will be accomplished through installing the solar panels and costs will be greatly saved. The achievement hasn’t ended! Since there is excessive energy, it is possible to transfer this amount to other areas like bedroom or entertainment area. Another prospective save will happen.
CONCLUSION AND RECOMMENDATIONS
Recommended solar panel
We recommend 235W HIT Hybrid Amorphous-Monocrystalline Module, Sanyo VBHN235SA06B, Anodized Aluminum Alloy, Silver, UL1703 certified, and California CEC listed. This low priced module is an easy way to get started with the solar power revolution. Its cost per Watt (after tax credit) was $1.49. It has 10 year workmanship and 20 year power output warranty. HIT Power Solar panels are leaders in sunlight conversion efficiency. Hybrid solar cells produce the highest output on cloudy days with 21.1% Cell Conversion efficiency and the most PTC Power 218.7 watts. As temperature rises, HIT Power produces 10% more electricity (kWh) than conventional crystalline silicon.
Apply the solar panel concept to the entire building
According to the results, we propose the use of recommended solar panels on the roofs of the entire building. It reduces operating costs and provides onsite energy to the hotel reducing the overall electricity demand on the grid, reducing the operating costs, while sending a strong message to guests of the hotels commitment to the environment.
Other sustainability recommendation to the hotel * Rammed Earth walls help to reduce the amount of stone used and integrate the site with the buildings. The lake pavilion’s curved walls and glass windows will store heat in the walls during the day while releasing them at night. * Radiant Heating use natural heat of the earth or any nearby hot spring and circulate the liquid through a concrete floor slab distributing heat to all floors and creating more efficient heating system for the hotel and the ancillary building. * Insulated Glazing Units (I.G. units) are double paned glass either air or gas filled to create a greater thermal barrier between the outside elements and the thermally controlled interior. These units should reduce operating cost significantly and keep the interior warmer during the winter and cooler during the summer. * External sun shading devices helps to cut down on direct sunlight and in the summer excess heat entering the building. * High SRI (Light colored materials) such as pavers cut down on the absorption of the sun’s infrared and ultraviolet wavelengths into the building and surrounding site which reduce the amount of heat on the surface of the ground and inside the building.
REFERENCES 1. http://www.freecleansolar.com 2. http://www.solarelectricsupply.com/solar-panels/sanyo/sanyo-hit-n235se10-soar-panels 3. http://www.heritagesolar.com/monocrystalline-polycrystalline-and-amorphous-solar-panels-2 4. http://www.solarhub.com/product-catalog/pv-modules/76 5. Rahnuma Siddiqui*, Usha Bajpai, “Deviation in the performance of Solar Module under Climatic parameter as Ambient Temperature and Wind Velocity in Composite Climate”, International Journal of Renewable Energy Research, Rahnuma Siddiqui et al., Vol.2, No.3, 2012 6. http://www.solarbuzz.com/facts-and-figures/markets-growth/market-share 7. http://www.livestrong.com/article/148653-which-countries-use-solar-energy/ 8. http://exploringgreentechnology.com/solar-energy/advantages-and-disadvantages-of-solar-energy/ 9. http://www.sfgate.com/business/prweb/article/Solar-Power-Generation-in-China-Industry-Research-4424238.php 10. http://www.seia.org/research-resources/us-solar-market-insight-2012-year-review
