▶I. Balcony Photovoltaics
Let's explore a topic together: residential solar power. Should we install solar panels? How much does it cost? For example, if I only have a three-square-meter empty balcony, can I install solar panels in that three square meters? The answer is yes; we should make the most of the space. Let's talk about the setup. How much electricity can three solar panels generate per day? Considering it's summer and air conditioning uses a lot of power, assuming each solar panel is 650W, three solar panels would be 3 * 650 = 1,950 watts. Calculating the sunshine duration from morning to evening as six hours, that would be 1,950W * 6H = 11.7 kWh, or 11.7 kilowatt-hours. A balcony power plant setup can generate 11.7 kWh a day. What can you use that 11.7 kWh for? Where does it go? For instance, a household refrigerator uses one to two kWh per day. A two-horsepower household air conditioner is approximately 1,800 watts. Running for five hours, it would consume about 9 kWh. So, installing three solar panels on your balcony can cover your refrigerator's daily electricity needs and even power a two-horsepower AC unit running at high power for five hours.
Many people will think this sounds great, so how much does it cost to set up balcony power plants? Actually, the cost is pretty low. For example, you'd need three solar modules, one micro-inverter, and one anti-backflow meter. If feasible, a small energy storage cabinet can also be added; a 5 kWh storage unit can cover most of a family's electricity needs. Why would you need battery storage? Because many people are not home during the day, any excess electricity generated can be stored for use when they return home in the evening.
▶II. Balcony Photovoltaic Costs
The cost of a photovoltaic system is influenced by factors such as module power, brand, region, and installation fees. The following is an estimate based on current market conditions, for reference only, not for precise financial calculations:
Photovoltaic Modules
Assumed parameters: Power per module: 400W. Unit price for mainstream brands (e.g., Longi, Jinko, etc.): approximately $1.0-1.5/W
Total cost for three modules:
400W × 3 × $1.2/W = $1,440
(Range: $1,200–$1,800)
Micro-inverter
Common models: Single-phase micro-inverter compatible with three modules (e.g., Enphase IQ7+, Hoymiles HM-300N)
Approximate unit price: $800–$1,500
(Prices may increase by 30% for every additional 1kW of power.)
Anti-backflow Meter
Function: Prevents power from flowing back into the grid (must comply with local utility grid requirements)
Approximate unit price: $500–$1,200
(Smart meters and branded models typically cost more.)
Energy Storage Battery
Type: Lithium iron phosphate battery (safer, longer lifespan)
Capacity:
5kWh (suitable for daily lighting, small appliances): $3,000–$5,000
10kWh (can support some nighttime power consumption): $6,000–$10,000
Brand differences:
Domestic brands (e.g., CATL, BYD): $1,000–1,300/kWh
Imported brands (e.g., Tesla Powerwall): $1,500+/kWh
Energy Storage Inverter/Controller
Function: Manages battery charging and discharging, needs to be compatible with the solar inverter.
Cost:
Integrated unit (combining PV and storage functions): $2,000–$5,000
Standalone energy storage inverter: $1,500–$3,000
Other Costs
Brackets/cables: approximately $300–$600
Installation labor: approximately $500–$1,000 (region-dependent)
Based on the above, the total cost ranges between $8,300 and $17,100. This means the investment cost for balcony power plants is comparable to commercial and industrial solar setups, and usually pays for itself in 4-5 years.
▶III. Solution Recommendations
Low-Cost Entry Option: 5kWh battery + domestic inverter, total cost approximately $8,000–$12,000. Ideal for storing energy during the day and powering low-wattage appliances at night.
High-Performance Option: 10kWh battery + integrated unit, total cost approximately $15,000–$20,000. Can handle short-term power outages or higher power demands.
We recommend contacting manufacturers for customized solutions and prioritizing integrated PV + storage products to reduce compatibility risks.
▶IV. Anti-backflow Meter
The balcony power plant anti-backflow meter is a wireless energy meter with an external current transformer and dual circuits. It is primarily designed for new energy generation systems such as grid-tied photovoltaic systems, micro-inverter systems, energy storage systems, and AC coupled systems. It offers advantages such as high accuracy, compact size, fast response time, and easy installation. It can monitor and measure electrical parameters like real-time power. It supports protocols such as Modbus-TCP and HTTP, and communicates with inverters or Energy Management Systems (EMS) via Wi-Fi and LoRa. This enables functions such as anti-backflow, power generation adjustment, and battery charging/discharging. It supports bidirectional metering, allowing for comprehensive energy management in residential distributed solar setups.