Introduction
Project Description:
The Penatahan project consists of 4 hectares located in the Penatahan district of Central Bali, Indonesia. This prayer + meditation center will have lodging + eating facilities for 40 persons within 1 year, expanding to 100 persons within 4 years. It is the desire of this retreat center to adhere to principles of local sustainability including 100% renewable energy. This assessment report outlines possible solutions to this energy quest. Background + further details are provided in the Appendix.
Energy Overview
The project area is blessed with an abundance of flowing water and rice: both great natural energy sources. It is important to keep an energy system as simple as possible to reduce up-front costs, improve reliability (reduce failures), reduce on-going O+M (operations + maintenance) costs, and for easier long-term understanding.
Energy systems are designed within the context of a community’s master plan and its values. All energy projects start downstream (demand, not supply): what useful (business) purpose does the end use provide, and how critical is it? (ie:food storage? illumination? Heating or cooling comfort?, etc) The first step is to minimize connected load and capacity needs without sacrificing business operations. This reduces the amount of energy supply needed, which is most important on RE (renewable energy) projects. The next step is to assess local, available and appropriate sources of energy. These energy resource choices will shape the rest of the energy and infrastructure for the project.
Penatahan Project Energy Overview
For this project, energy usage can be kept to a minimum by providing only food services and night time illumination. Acoustic + visual stimuli may be of primary concern to enhance each visitor’s experience. As a learning center, the project can showcase leading edge RE systems in full operational use and familiarize locals with these technologies, while remaining integrated with its natural surroundings and age-old, local practices. Specific costs and ROI tradeoffs will be provided in the feasibility study once an energy infrastructure has been selected.
Summary Recommendation
It is recommended that the Penatahan project puts infrastructure in place to allow for future energy infrastructure enhancement at minimal first cost. Configuration scenarios and RE availability Tables are provided, from which a choice needs to be made of which combination
local, renewable resources will be used.
CARTOON HERE...
Renewable Energy reSource Assessment summary
Summary assessment of resources available on-site (CMG order)
- Biomass fuel is available from local rice and coconut husks.
- Ample Solar hot water is readily available at very low cost.
- Geothermal is marginal due to moisture and unknown temps.
- Biogas is plentiful from nearby chicken farmers.
- Abundant Hydro is available from the subak canal system.
- Solar PV is available, but expensive (per watt).
- Wind is available for ventilation + cooling, not as direct power.
TABLE 1: Energy Harvesting + Availability Chart @ Penatahan
A. Local availability 10 = hi | B. Harvesting Cost/watt 10= hi | C. Energy Yield 10 = hi | D. First Cost 10= hi | E. Operations Cost 10=hi | F. Ease of Operation 10 = easy | |
1. Biomass | 10 | 3 | 10 | 10 | 9 | 2 |
2. Solar Hot Water | 10 | 1 | 6 | 3 | 1 | 7 |
3. Geothermal | 5 | 2 | 3 | 2 | 1 | 8 |
4. Biogas | 9 | 5 | 8 | 5 | 5 | 4 |
6. Micro Hydro | 9 | 5 | 7 | 7 | 6 | 5 |
7. Solar PV | 7 | 7 | 4 | 8 | 3 | 9 |
8. Wind | 2 | 10 | 7 | 7 | 2 | 6 |
Like any system, each RE technology has
its pros + cons. For example:
Small Scale Biomass requires a knowledgeable operator, and given its large power output potential with ample local rice husk supply, it should be given serious consideration for the future.
Biogas is an accepted, local technology. But given the vegetarian focus of this project,
using chickens may not be appropriate,and human waste is a ‘drop in the bucket’
along with other issues such as C:N ratio, sawdust addition, etc.
TABLE 2 Penatahan RE possible scenarios
A | B | C | D | E | F | |
Simplest | Simple | Medium 1 | Medium 2 | High 1 | High 2 | |
Nite Lighting | LEDflashlights | Solar PV | Solar PV | Solar PV | 3 sources* | 3 sources* |
Food Prep | LPG tank | LPG tank | Biogas | biogas | biogas | biogas |
Food Storage | Ice Coolers | Ice Coolers | Solar PV | Solar PV | 3 sources* | 3 sources* |
TeleData | ~100w PV | ~ 200w PV | ~500w PV | >1000W PV | 3 sources* | 3 sources* |
Hot water | none | none | Solar HW | Solar HW | Solar HW | Solar HW |
ElectrStorage | none | SmallBattery | Med Battery | MedBattery | LargeBattery | Golf Carts |
~relative Power needs | 1a | 10a | 20a | 40a | 100a | 200a |
~relative Front Cost | 2000 | 4000 | 6000 | 25000 | 35000 | 50000+ |
~relative Annual O+M | 2400 | 3000 | 5000 | 6000 | 15000 | 18000 |
* 3 sources = MicroHydro, Biomass genset, Solar PV
TABLE 3 Penatahan Available energy + economic yield potential
A. Avail.Energy | B. units | C. joules | D. watts/day | E. $0.10/kwh | F. $/year | |
1. Biomass | 80000 | watts/day | 2.88E+08 | 80000 | 8 | $2,920 |
2. Solar Hot Water | 16500 | btu/day | 1.74E+07 | 4832 | 0.4832 | $176 |
3. Geothermal | 2880 | btu/day | 3.04E+06 | 843 | 0.0843 | $31 |
4. Biogas | 4392 | Mbtu/day | 4.63E+09 | 18000 | 1.8 | $657 |
6. Micro Hydro | 1200 | watts/day | 4.32E+06 | 1200 | 0.12 | $44 |
7. Solar PV | 6250 | watts/day | 22.50E+06 | 6250 | 0.625 | $228 |
TOTALS | 4.948E+09 | 106125 | $4,056 |
After all RE analyses are done,it is important to layout and design an RE system infrastructure that will readily accommodate future technologies and controls, along
with expansions of other phases or uses.
APPENDIX
Energy Site data
Ceres[1]Project Stats
Climate: Equatorial
Location: Lat -8.565o Long 115.164o Elevation: 73m
Average Mean Incident Radiation: 5.33 KWH/m2/day
Min. Avg Insolation over 7 day period: 63.4%
Average skin temp: ~28o C
Average Wind Speed: 4-7 m/s (8-15 mph)
Avg Rainfall: 0.53 – 8.89 mm/d (0.02 – 0.35 in/day)
TABLE 4 Empirical Subak Canal Flow MeasurementsSeconds = 20 liter bucket | Raw Data | full width flow | |||||||||||||
#1 | #2 | #3 | #1 | #2 | #3 | Total Flow: Liters/min | |||||||||
3.3 | 15.1 | 5.4 | 3.3 | 15.1 | 5.4 | 13.2 | 45.3 | 10.8 | 90.9 | 26.5 | 111.1 | ||||
3.8 | 17.4 | 4.7 | 3.8 | 17.4 | 4.7 | 15.2 | 52.2 | 9.4 | 78.9 | 23.0 | 127.7 | ||||
3.4 | 17.9 | 4.2 | 3.4 | 17.9 | 4.2 | 13.6 | 53.7 | 8.4 | 88.2 | 22.3 | 142.9 | ||||
3.2 | 16.4 | 5.0 | 3.2 | 16.4 | 5.0 | 12.8 | 49.2 | 10.0 | 93.8 | 24.4 | 120.0 | ||||
total | 351.8 | 96.2 | 501.6 | ||||||||||||
Avg | 88.0 | 24.1 | 125.4 | ||||||||||||
Energy Resources available:
1. 2,000 chicken farm is close by
2. one ton+ per day of super-dry rice husks available at ~5,000 rupiahs/bag
3. Water flow (see Table 4 above) is available from subak canals.
3. Coconut husks are available – quantity unknown.
4. PNL power available about 1 km away.
5. LNG/Propane can be delivered in ___ liter (___ ft3 of LNG) bottles at $7/bottle?
6. Solar and Wind resources are specified above in ‘Project Stats’
Background Information
Long Version:
Ranking of seven renewable resources with lowest life-cycle costs:
(1) The best RE is Solar hot water. Its use will be for domestic hot water and distilling water. Food prep and resident showers should be powered by 100% SHW. It is cheap and relatively easy to adapt within new construction.
(2) Biogas is a locally accepted RE technology with adequate local supply. A small barrel with delivered waste product will easily supply all the cooking gas needs.
(3) Micro-hydro from the subak canals and its endless supply of continuous flowing water presents the largest RE opportunity at the site. However, its reliability and the political nature of the subak system may pose long-term issues.
(4) Solar PV with appropriate controls, inverter and battery bank system can be easily adapted to the project site in various configurations, awnings, ground mounted, etc.
(5) Biomass has the best long-term potential for the substantial amount of energy is produces, and the sheer volume of very lo-cost rice husks that are available. It requires knowledgeable O+M operators.
(6) Geothermal may provide some minimal contribution to cooling, especially in the food storage areas. It has low initial cost and minimal O+M cost.
(7) Wind is way below the minimal threshold, and appears not to be feasible for any substantial power contribution.
Location + Environs:
The Muspa Metapa project is located in Central Bali, adjacent to Mongan Village, at the foot of Mt. Batu karu. The location is referred to as: Penatahan, Penebel, Tabanan Regency, Bali, IndonesiaIt is close to the village of Dusun Bedugal (to the south),
and further along is the medium sized village of Penatahan.
The closest main city is Tabanan which is the capital of the
district (readily found on google maps). The local jurisdiction
is the IMB the Indonesian building authority with offices in
Tabanan.Topography of site is varied with many ~1m
contoured terraces and small flat areas Local farming
community, nearby villages.
Energy Conversion Units
Joule (J) : energy expended when 1 kg is moved 1 m by a force of 1 Newton or in passing an electric current of one ampere through a resistance of one ohm for one second. [a joule is the accepted standard unit of energy used in human energetics within the International System of Units (SI).]
Power = Volts (pressure) X Amps (flow)
1 therm = 100,000BTU
1 BTU = 1,055 Joules
1 Watt Hour = 3600 Joules
1 KWH = 3413 BTU
1 HP = 0.746 KWH
