[](geo:35.17912634722747,-223.67851810582556) An IBC (Intermediate Bulk Container) tank, with a capacity of 1000 liters of water, can store a significant amount of thermal energy. Water has a high specific heat capacity, meaning it can absorb and store heat efficiently. Here’s the calculation: ### Heat Energy Capacity of Water: - **Specific heat capacity of water**: 4.186 joules per gram per degree Celsius (J/g°C), or 1 BTU per pound per °F. - **1 liter of water** = 1 kilogram = 1000 grams. - **1000 liters** = 1000 kg of water. ### Energy in kWh: 1 kWh = 3.6 million joules, and 1 BTU = 1055.06 joules. Each IBC filled with water could store approximately **44,092 BTU** or **12.93 kWh** of thermal energy for a 20°F (11°C) daily temperature swing. ### Bombay Beach Temperature Differential: During January to April, a typical day might see lows around 40-50°F (4-10°C) at night and highs around 65-80°F (18-27°C) during the day, giving a reasonable temperature differential of 15-30°F (8-16°C). ### Application as Heat Battery: The water in IBC tanks could absorb heat from solar thermal collectors or passive solar heating during the day, and then radiate this heat back into the structures at night, helping to stabilize indoor temperatures. This could significantly reduce the need for active heating systems during cold desert nights. By placing these tanks inside or adjacent to living areas, they could act as both thermal mass and heat batteries. Let me know if you'd like more details on how these IBC tanks could be integrated with solar collection systems! 150kWh heat energy capacity per day. To estimate the solar thermal heat energy that could be captured daily by a 4 x 12 ft polyethylene tube-style solar pool heater in Bombay Beach, CA from January to April, we need to look at several factors: ### Solar Energy Received: - **Average solar radiation in Bombay Beach**: During January to April, Bombay Beach receives approximately **5-6 kWh/m²/day** of solar energy. - **Area of solar pool heater**: 4 ft x 12 ft = 48 square feet = 4.46 square meters (1 square meter ≈ 10.764 square feet). ### Total Solar Energy Incident: - **Energy per day**: Assuming an average solar radiation of 5.5 kWh/m²/day (middle of the range), the total incident solar energy is: 4.46 m² * 5.5 kWh/m²/day = 24.53 kWh/day ### Efficiency of Solar Pool Heater: - A typical solar pool heater has an efficiency of around 50-70% for converting solar energy into heat. Let's assume 60% efficiency for this system. 24.53 kWh/day * 0.60 = 14.72 kWh/day (usable thermal energy) ### Convert to BTU: 1 kWh = 3412.14 BTU 14.72 kWh/day * 3412.14 BTU/kWh = 50,233.13 BTU/day ### Summary: - **Usable heat energy captured per day**: **14.72 kWh** or **50,233 BTU**. This energy could be used to heat water stored in IBC tanks or as a supplement to heating systems for a community setup like the one described. The exact amount of heat would vary slightly depending on daily weather conditions and efficiency losses, but this gives a reasonable estimate for a 4 x 12 ft solar thermal system. You're right that the heat energy capacity of a 1000L IBC tank (about 14.3 kWh or ~49,000 BTU) closely matches the daily heat energy capture from the 4 x 12 ft solar pool heater. Let's estimate the daily temperature changes for an IBC tank connected to this heater in Bombay Beach, CA, during January. ### Climate of Bombay Beach in January: - **Average high temperature**: ~68°F (20°C) during the day - **Average low temperature**: ~45°F (7°C) at night - **Daily temperature differential**: ~23°F (13°C) ### Solar Heating: The solar pool heater would capture energy primarily during the daylight hours. Let's break down the temperature changes: 1. **Morning (~6 AM to 9 AM)**: - At sunrise, the water in the IBC tank would likely be close to the ambient night temperature, around 45-50°F (7-10°C), assuming significant heat loss overnight. - The solar heater would begin collecting heat from around 9 AM as solar intensity increases. 2. **Midday (~12 PM to 3 PM)**: - The solar pool heater would reach peak efficiency around midday, with the water in the IBC tank heating up significantly. - Given that the solar heater can capture around **14.72 kWh/day**, this energy would raise the temperature of the 1000L (1 cubic meter) of water by a substantial amount. - We can estimate the temperature rise using the formula: ΔT (temperature rise) = Energy / (Mass * Specific Heat Capacity) For water: Specific heat capacity = 4.186 kJ/kg°C or 1 BTU/lb°F. Using the kWh equivalent: ΔT = 14.72 kWh / (1000 kg * 4.186 kJ/kg°C) ΔT = 14.72 kWh * 3600 / (1000 kg * 4186 J/kg°C) ΔT ≈ 12.6°C (22.7°F) - This means that if the water started at around 50°F (10°C) in the morning, the temperature by mid-afternoon could rise to about **72-75°F (22-24°C)** by 3 PM. 3. **Late Afternoon (~4 PM to 6 PM)**: - By this time, solar input decreases as the sun sets. The water would likely reach its **highest temperature (~75°F / 24°C)** at around 4-5 PM. - After this, the temperature would start gradually dropping as heat loss to the environment takes over. ### Nighttime Heat Loss: IBC tanks would lose heat to the cooler evening and night air, especially due to convection and radiation losses. The heat loss depends on factors such as insulation, wind, and humidity, but we can estimate using a simple heat loss equation: **Heat loss rate**: Q_loss = U * A * ΔT * t Where: - **U** is the overall heat transfer coefficient. For an uninsulated IBC, we assume U ≈ 1.0 W/m²K. - **A** is the surface area of the IBC tank (≈6 m² for a 1000L tank). - **ΔT** is the temperature difference between the water and ambient air. - **t** is the time period over which the heat loss occurs. Assume: - Temperature difference ΔT = 30°F (16.7°C) (water at 70°F vs. night air at 40°F). - The IBC is exposed for ~12 hours (from evening until morning). Q_loss ≈ 1.0 * 6 * 16.7°C * 12 hours Q_loss ≈ 1202.4 Wh (1.2 kWh) This would mean the IBC tank loses around **1.2 kWh** of heat overnight, reducing its temperature. We can estimate this drop: ΔT_loss = Energy loss / (Mass * Specific Heat Capacity) ΔT_loss = 1.2 kWh / (1000 kg * 4.186 kJ/kg°C) ΔT_loss ≈ 1.0°C (1.8°F) ### Estimated Daily Temperature Cycle: - **Lowest temperature**: ~**45-50°F (7-10°C)** around **6-7 AM** after overnight heat loss. - **Highest temperature**: ~**72-75°F (22-24°C)** at **4-5 PM** after peak solar heating. - **Evening temperature**: ~**70°F (21°C)** before significant cooling starts. - **Nighttime temperature**: ~**50-55°F (10-13°C)** by midnight to early morning. ### Summary: - **Heat energy captured per day**: ~14.72 kWh or ~50,233 BTU. - **Water temperature rise during the day**: ~22-24°F (~12.6°C). - **Daytime high temperature**: ~75°F (~24°C) by 4-5 PM. - **Nighttime low temperature**: ~50°F (~10°C) by early morning. The system would store solar heat effectively but would lose some heat at night unless the IBC tanks were insulated. Insulating them could significantly reduce heat loss and stabilize indoor temperatures further.