光伏发电和负荷用电相对同步，自发自用比例高，电价相对较高，投资等优势，成为大家眼中的香饽饽，但是，并不是每一个屋面都适合安装

Photovoltaic power generation and load electricity consumption are relatively synchronized, with a high proportion of spontaneous self use, relatively high electricity prices, and high investment returns, which have become a hot topic in everyone's eyes. However, not every roof is suitable for installation

光伏电站

Photovoltaic power station

要确定房屋产权企业经营情况用电量；其次就要实地勘探屋面条件，要确认屋顶的承载能力屋面设备情况女儿墙高度周边是否有高层建筑物；还有厂房的电网环境供配电设施等等。如果前期没有勘探清楚，盲目建设，有可能造成重大损失。

Firstly, it is necessary to determine the operating situation and electricity consumption of the property rights enterprise; Secondly, it is necessary to explore the roof conditions on the spot, and confirm the bearing capacity of the roof. Whether there are high-rise buildings around the height of the parapet; There are also power supply and distribution facilities in the power grid environment of the factory building. If there is no clear exploration in the early stage and blind construction, it may cause significant losses.

建筑屋顶的产权

Property rights of building roofs

如果投资方不是建筑物的业主，要注意建筑物的产权归属，如果是政府机关学校医院车站等公共建筑，产权明确无争议，则适宜开发；

If the investor is not the owner of the building, attention should be paid to the ownership of the building's property rights. If it is a public building such as a government agency, school, hospital, station, etc., and the property rights are clear and undisputed, it is suitable for development;

建筑屋顶的寿命

The lifespan of building roofs

光伏电站需要运营25年，一般要8-10年左右才能收回全部成本，在项目开发时，需要了解屋顶能使用的年限，年限太短不适宜进行开发，一般要超过20年。

Photovoltaic power plants require 25 years of operation, usually around 8-10 years to recover the full cost. During project development, it is necessary to understand the lifespan of the roof. If the lifespan is too short, it is not suitable for development, usually exceeding 20 years.

建筑屋面荷载

Building roof load

屋面荷载分为恒荷载和可变荷载。恒荷载是指结构自重及灰尘荷载等，光伏电站需要运营25年，其自重属于恒荷载。通常钢结构厂房上装光伏系统每平米会增加15公斤的重量，砖混结构厂房的屋顶每平米会增加80公斤的重量。可变荷载是考虑状况下暂时施加于屋面的荷载，分为风荷载雪荷载地震荷载活荷载等。

The roof load is divided into constant load and variable load. Dead load refers to the self weight of the structure and dust load. Photovoltaic power plants require 25 years of operation, and their self weight belongs to dead load. Usually, installing a photovoltaic system on a steel structure factory building adds 15 kilograms of weight per square meter, while the roof of a brick concrete structure factory building adds 80 kilograms of weight per square meter. Variable load refers to the load temporarily applied to the roof under consideration, which is divided into wind load, snow load, seismic load, live load, etc.

建筑用电量及用电价格

Building electricity consumption and electricity prices

工商业光伏发电投资价值高，重要的是工商业电价高，如一般工商业高峰电价是1.15元/度，自发自用比例高，一般工商业高峰时段是8：00~22：00，这个时段和光伏发电基本同步。因此要统计建筑物的用电情况，有一些企业用电量大，如大型商场写字楼车站码头等商业区。

The investment value of industrial and commercial photovoltaic power generation is high, and what is important is the high electricity price of industrial and commercial industries. For example, the peak electricity price of general industrial and commercial industries is 1.15 yuan/kWh, and the proportion of spontaneous self use is high. The peak hours of general industrial and commercial industries are from 8:00 to 22:00, which is basically synchronized with photovoltaic power generation. Therefore, it is necessary to calculate the electricity consumption of buildings. Some enterprises have high electricity consumption, such as large shopping malls, office buildings, stations, docks, and other commercial areas.

化学原料制品非金属矿物制品黑色金属冶炼和有色金属冶炼模具加工热处理电镀等工厂，这些高能耗企业同时也非常需要光伏发电来降低它的能耗指标。但也有一些企业用电比较少，如物流园仓储等，这些建筑往往面积很大，但本身没有什么设备，用电量很少，安装光伏后只能大部分上网卖电，也不适合投资。

Chemical raw material products, non-metallic mineral products, black metal smelting, and non-ferrous metal smelting, mold processing, heat treatment, electroplating and other factories. These high-energy consuming enterprises also greatly need photovoltaic power generation to reduce their energy consumption indicators. But there are also some enterprises that use relatively little electricity, such as logistics parks and warehouses. These buildings often have a large area, but they do not have much equipment and use very little electricity. After installing photovoltaics, most of them can only sell electricity online, which is not suitable for investment.

建筑物内的电网质量

Quality of power grid inside buildings

光伏逆变器

Photovoltaic inverter

向电网输送电能，电网质量的好坏也会对逆变器产生影响，在一些机械加工厂，有吊车电焊机龙门铣床等大功率设备，和一些电弧炉等设备开，在启动和关断之间，电能变化非常剧烈，电网来不及调整，同时伴随大量的谐波，电网中存在的谐波和不平衡负序分量将导致光伏系统输出有功功率波动。由于光伏逆变器输出都是有功功率，如果建筑物内有些设备需要无功功率，只能由电网来提供，因此当光伏系统工作时，有可能造成企业无功功率超标，力调电费增加的事情发生。

The transmission of electrical energy to the power grid can also have an impact on the quality of the inverter. In some mechanical processing plants, high-power equipment such as cranes, welding machines, gantry milling machines, and some electric arc furnaces are turned on. Between startup and shutdown, the changes in electrical energy are very drastic, and the power grid cannot be adjusted. At the same time, a large number of harmonics and unbalanced negative sequence components in the power grid will cause fluctuations in the output active power of the photovoltaic system. Due to the fact that the output of photovoltaic inverters is all active power, if some equipment in the building requires reactive power, it can only be provided by the power grid. Therefore, when the photovoltaic system is working, it may cause the reactive power of the enterprise to exceed the standard and increase the power regulation electricity bill.

质量较差的地方安装光伏系统，需要增加电能质量改正的设备，如有源滤波器APF,静止无功发电器SVG等，并对这些设备和电网的参数进行实时监控。逆变器的并网点尽量远离用电设备，如直接升压到中压10kV并网，可以回避谐波等电能质量风险。

Installation of photovoltaic systems in areas with poor quality requires the addition of equipment for power quality correction, such as active power filters (APFs) and static reactive power generators (SVGs), and real-time monitoring of these equipment and grid parameters. The grid connection point of the inverter should be as far away from the electrical equipment as possible, such as directly boosting to the medium voltage 10kV grid connection, which can avoid power quality risks such as harmonics.

配电设施及并网点

Distribution facilities and connection points

配电设备是光伏电站选择并网方案的根据之一，主要考查内容有厂区变压器容量数量母联负荷比例等。

Distribution equipment is one of the basis for selecting grid connection schemes for photovoltaic power stations, mainly examining the capacity, quantity, and load ratio of transformers in the factory area.

虽然新标准取消了光伏容量要小于变压器容量百分之25的限制，而且还没有规定上限是多少，但是根据经验，当光伏容量超过变压器容量百分之70时，工厂内电能质量会下降很多，因此建议光伏容量不要超过变压器容量百分之70。

Although the new standard has abolished the limit of 25% less photovoltaic capacity than transformer capacity, and has not yet specified the upper limit, based on experience, when photovoltaic capacity exceeds 70% of transformer capacity, the power quality in the factory will decrease significantly. Therefore, it is recommended that photovoltaic capacity not exceed 70% of transformer capacity.

工商业可选择单点并网和多点并网，各有好处，单点并网是集中在一起，便于管理，多点并网是多个地方就近并网，交流线路短，效率高。可根据实际情况来选择。

Industry and commerce can choose between single point grid connection and multi-point grid connection, each with its own advantages. Single point grid connection is centralized and easy to manage, while multi-point grid connection is connected to multiple nearby places, with short communication lines and high efficiency. You can choose according to the actual situation.