What are the solutions for smart valve power supply in agricultural irrigation applications

In agricultural irrigation scenarios, the stable power supply of intelligent valves (such as electric valves) is the core guarantee for their reliable operation. Due to the characteristics of wide area, weak power infrastructure, and complex terrain in agricultural environments, traditional municipal power supply has problems such as high wiring costs and difficult maintenance. Therefore, it is necessary to choose flexible and efficient power supply solutions based on the characteristics of the scenario. The following are common intelligent valve power supply solutions, covering various technological paths such as new energy, energy storage, and on-site energy harvesting, and analyzing their applicable scenarios and advantages and disadvantages:
1、 Solar power supply system
Solar energy is the most commonly used new energy supply method in agricultural irrigation scenarios, especially suitable for areas with sufficient sunlight such as open fields, orchards, tea gardens, etc. It has the advantages of being clean, renewable, and on-site energy harvesting.
Core composition
Solar panels: Select monocrystalline/polycrystalline silicon panels based on the power of the smart valve (usually 5-50W), with a power range of 10-100W (matching daily power consumption).
Energy storage battery: stores excess electrical energy to cope with low light conditions such as cloudy days and nighttime. It is commonly used with lithium batteries (such as lithium iron phosphate, which has a long lifespan and high energy density) or lead-acid batteries (which are low-cost and suitable for low-frequency use). The capacity is designed based on the daily power consumption multiplied by the number of backup days (usually 3-7 days).
Energy management module: includes charge and discharge protection, voltage conversion (such as 12V/24V output), light control/time control wake-up function, to avoid overcharging and overdischarging of the battery and extend its lifespan.
Applicable scenarios
Open areas with sufficient sunlight (such as plain farmland, mountain orchards).
The working frequency of intelligent valves is moderate (such as opening and closing 3-5 times a day), and the single working time is short (a few seconds to a few minutes).
advantages and disadvantages
Advantages: No wiring required, long maintenance cycle (battery life of 2-5 years), low operating costs.
Disadvantages: It is greatly affected by weather conditions (power outages may occur during continuous rainy days), and the initial equipment cost is relatively high (about 300-1000 yuan/set).
2、 Battery direct supply system
For smart valves with low power (≤ 10W) and low operating frequency (such as opening and closing 1-2 times a day), battery power can be directly used without the need for complex energy conversion equipment, making them suitable for short-term use or small-scale scenarios.
Common battery types
Lithium batteries: such as 18650, 26650 and other models, with a voltage of 3.7V (can be connected in series to 12V), high energy density, and a range of 3-12 months (depending on power consumption).
Alkaline dry batteries, such as AA/AAA batteries, have low cost and are suitable for ultra small power smart valves (such as communication only), but have short battery life (1-3 months) and frequent replacement.
Lead acid battery: voltage 12V/24V, large capacity (12-100Ah), suitable for slightly high-power intelligent valves, but heavy (inconvenient to transport) and short lifespan (1-2 years).
matlab
Adopting low-power chips (such as STM32L series) and sleep wake-up mechanism (only waking up during operation, standby current ≤ 10 μ A) to reduce standby power consumption.
Equipped with a battery monitoring module, remote reminders for battery replacement are provided through wireless communication (LoRa/NB IoT) to reduce manual inspection costs.
Applicable scenarios
Small scale greenhouses, potted irrigation, or temporary experimental fields.
Intelligent valves only need to work intermittently (such as once a week).
advantages and disadvantages
Advantages: Low initial cost (about 50-200 yuan for battery and protection circuit), flexible deployment.
Disadvantages: Limited battery life, requiring regular replacement/charging (high labor cost), not suitable for high-frequency work scenarios.
3、 Wind energy/wind solar complementary power supply system
In windy areas such as plateaus, mountainous regions, and coastal farmland, wind energy can serve as a supplement to solar energy or even provide independent power supply; The wind solar complementary system can combine the advantages of both and improve power supply stability.
Core composition
Small wind turbines: with a power of 10-100W (such as vertical axis fans, suitable for low wind speeds), output DC 12V/24V.
Solar panels: complement wind energy (use solar energy on sunny days, use wind energy on cloudy/nighttime days).
Energy storage battery+controller: Same as the solar energy system, the controller needs to support both wind and solar inputs, with priority given to using wind or solar energy (based on real-time energy levels).
Applicable scenarios
Areas with high altitude and less wind and rain (such as northwest farmland and grassland irrigation).
The working frequency of intelligent valves is relatively high (such as opening and closing more than 10 times a day), and stable power supply is required.
advantages and disadvantages
Advantages: Power supply stability is better than single solar energy, suitable for complex climate areas.
Disadvantages: The cost of the fan is relatively high (about 500-2000 yuan), and the installation location needs to be considered (to avoid obstruction). Maintenance is also complex (the fan is prone to dust accumulation and blade wear).
4、 Hydroelectric power supply system
If intelligent valves are deployed near irrigation channels and pipelines (such as drip irrigation main pipelines and open channels), they can use water flow energy to drive small hydroelectric generators, achieving “on-site energy harvesting”, especially suitable for scenarios with water all year round.
core technology
Micro hydro generators: divided into pipeline type (installed in irrigation pipelines, utilizing water pressure difference) and channel type (floating on the surface of the channel, utilizing water flow thrust), with a power of 5-50W and an output of 12V/24V DC.
Energy storage coordination: Due to the possibility of unstable water flow (such as water during irrigation periods and interruption during non irrigation periods), small batteries (such as 12V/20Ah lithium batteries) need to be used to store electrical energy.
Applicable scenarios
Irrigation channels with year-round water supply, farmland downstream of reservoirs, or near the main pipelines of drip/sprinkler irrigation systems.
Intelligent valves require long-term continuous operation (such as real-time monitoring of flow and dynamic adjustment).
advantages and disadvantages
Advantages: Free and stable energy (when the water flow is continuous), no need to rely on weather.
Disadvantages: Due to irrigation cycle limitations (unable to generate electricity when there is no water), installation requires modification of pipelines/channels (which may affect irrigation efficiency).
5、 Energy harvesting technology (ultra-low power consumption scenario)
For ultra-low cost intelligent valves that only require intermittent communication (such as reporting status) and almost no need to drive valve action (such as pure sensing+wireless feedback function), energy harvesting technology can be used to achieve “zero maintenance” power supply.
Common techniques
Vibration energy harvesting: Utilizing the mechanical vibration of irrigation pumps and pipelines, the vibration is converted into electrical energy (power level of μ W) through piezoelectric ceramic plates.
Temperature difference energy collection: Utilizing the temperature difference between soil and air (such as soil temperature being higher than air during the day), power is generated through thermoelectric generators (TEG)