Contents (Jump to)

CHAPTER 3

Solar and wind technologies comparison

3.1 Economics of technologies

3.1.1 Cost of photovoltaic Cells

3.1.1 Economics of wind turbines

3.2 Efficiency of technologies

3.3 Advantages and disadvantages

CHAPTER 4

RESULTS AND DISCUSSION

4.1Results

4.2Discussion

CHAPTER 5

CONCLUSION AND RECOMMENDATION

5.1Conclusions

5.2Recommendation

REFERENCES

CHAPTER 2

Solar and Wind Technologies Comparison

3.1 Economics of technologies

Installed cost and performance levels of renewable energy plants are similar around the world, although no single figure can quantify the precise cost and performance of any renewable technology. The location where the technology is installed plays a major role in providing the energy resource for renewable energy technologies. Solar installations close to the equator have more energy production capability. Wind energy variations are more extreme, windiest regions are favorable to install wind turbines that generates significant amount of electrical energy such as New Zealand and United Kingdom (Freris and Infield, 2008).

Table 3.1 shows the main parameters related to renewable energy technologies and conventional plant. It also indicates the three major components of energy generation cost which are: (1) the cost of the plant, land acquisition, grid connection and initial finance cost, (2) operation and maintenance cost (O&M) and finally fuel cost. From the table it is noticeable that most of the renewable energy technologies have zero fuel cost and it varies in conventional plant.

Table 3.1: Comparison of cost and performance data for renewable energy and conventional plant (Freris and Infield, 2008)

Levelized cost method is the main traditional approach used to compare cost generating electricity from various energy technologies. The levelized cost of energy technologies is measured as it is shown in Equation 3.1:

LOCE = (Eq. 3.1)

The LCOE method is concept from reality and is used as a ranking tool to measure the cost-effectiveness of various energy generation technologies. Where CF is the capacity factor; OC is the overnight construction cost; CRF is the capital recovery factor; OMC is the series of annualized operation and maintenance costs; FC is the series of annualized fuel costs; r is the discount rate and T is the economic life of the plant.

3.1.1 Cost of photovoltaic Cells

Solar radiation is a finite and free source of energy but despite that, there is cost for utilizing this form of energy. The calculation of the cost of solar energy can be made in the following manner. Assuming the solar system would have a specific lifetime of T years at initial cost of C₀ Dollar. The amount of energy the system can generate during the lifetime of the system is Q (Goswami et al., 2000). The unite cost of energy, neglecting the interest charges, is equal to the cost of the installation divided by the total energy generated during the lifetime as it is shown in Equations 3.2:

C_s = (Eq. 3.2)

For example if the solar energy collector cost $200/m² , has an expected life of 20 years, and is installed in a location where the mean annual horizontal surface irradiance is 300 W/m² averaged over 24 hours, the cost of solar energy C_s will be equal to:

=

= $0.00380/Kw.hr

However it is clear that no solar energy collector can perform at 100% efficiency. According to thermodynamic laws only a fraction of incident energy can be transformed into useful heat. Assuming the efficiency of the collector Æž_c is 40 percent, the cost of solar will be given by Equation 3.2:

C_s = = $0.00951/Kw.hr (Eq. 3.3)

The efficiency of photovoltaic device plays a major role in the cost of the technology as we notice from the previous equation along with the optic of the device. The price of photovoltaic materials is usually expressed on a per-unit-area basis but the units are often sold based on cost per watt that is generated under peak solar illumination conditions. Equation 3.4 is used to convert the cost per square meter to cost per watt for photovoltaic technologies:

$/W_P = (Eq. 3.4)

The return on investment made for specific equipment or material used for the photovoltaic system also is estimated. The payback time of PV unite of cost $/m², is associated with the efficiency of the system, the installation location and the price of at which electricity generated is sold on the market $/kWh. Equation 3.5 is used to estimate the payback time which is:

Payback time = (Eq. 3.5)