## 5 Case Study
### Evaluation Result Analysis  
With the weighting results in Equation (22), the TOPSIS evaluation model can be used to assess the core abilities of these 3 distributed PV-generation projects. In Figure 6, the differentials of core abilities for each distributed PV project can be seen in every dimension.  
1. Investment and earning ability. Influenced by installed capacity, project B has the best performance in investment and earning ability. From the indicators of effective rate of return and static payback period, the abilities of project A are better than that in the other two projects. Project C has an advantage in return on equity. The evaluation results of investment and earning ability in each project are 0.5317, 0.8149 and 0.0873, respectively.
2. Production and operation ability. From the evaluation conclusions, it can be found that the installed capacity with scale-production benefits has significant effects on production and operation ability. For example, the unit operation and maintenance cost of project B is just 0.018 yuan/kWh due to its largest installed capacity in these three projects. Meanwhile, rich resources also influence production and operation ability. At project A in north-western China, rich solar energy promotes the efficiency of the generation system up to 87%. The evaluation results of production and operation ability in projects A, B and C are 0.3398, 0.8732 and 0.1171, respectively.  
Figure 5: Weighting result comparison with different methods.  
Power grid coordination ability. Based on the investigation in the feasibility report, power grid coordination ability is mainly determined by policy. In 2016, most of provinces in China developed a purchasing policy for renewable and clean generation power which improve the power supply structure. Due to its own electric power system, project A has better performance in terms of coordination ability on the aspects of grid-connected power quantity and loss rate of the power grid. Projects A, B and C's evaluation results for power grid coordination ability are 0.5782, 0.3441 and 0.0519, respectively.
* Energy-conservation and emission-reduction ability. Similar to production and operation ability, project B saves more coal and reduces more pollutant. The environmental effect on energy-conservation and emission-reduction in project B is obvious. On the contrary, project A and C did not yet demonstrate their best environmental benefit. The evaluation results of energy conservation and emission reduction are 0.3645, 0.9763 and 0.0450 in projects A, B and C, respectively.
* Sustainable development ability. Project A has the best evaluation result in _EVA_ that can amount to 14.3 million yuan annually. Meanwhile, project A also shows its competitiveness on the increasing rate of local load. With greater acceptance of renewable power to the power grid, the ratio of renewable energy in the power supply structure has increased stably. Due to the technology improvement in micro-grids in particular, the potential of distributed generation projects has grown even further. The evaluation results of each project in the sustainable development ability are 0.3999, 0.2123 and 0.3833.
* Society-serving ability. Project A provides more employments than projects B and C. On the aspect of increasing rate of local GDP, location C has a better economic development environment which can promote the development of a distributed generation project. Project B generates more renewable energy for the local power supply increment. Therefore, the society-serving ability of project B has the best evaluation result among these three projects. The evaluation results of the society-serving ability are 0.4066, 0.4834 and 0.3234.  
Figure 6: Core abilities evaluation results of each distributed PV project.