I saw somewhere (kwa gazeti i think, kitambo kidogo and will definately be political) ati initial feasibility studies showed the hydroelectric dams were more suitable for rivers in western kenya due to lower sediment loads than mtkenya region but were moved due to geopolitics. If true and increased deforestation and poor farming practises around/along the tana then siltation could be a big problem in those reservoirs.
** hio inanipea idea ya ka-proposal, wacha niongee na majaa wengine hapa ma guru wa GIS**
:D:D:D:D
I remember reading that article sometime back. Western Kenya was ideal due to vegetation cover, which means lower levels of erosion.
Compared to the tana delta, which the surrounding is sandy and semi arid. Meaning high soil erosion.
Then it could be interesting to do sedimentation studies on the reservoirs. Alafu uki-publish uhame kenya
I know, I have a feeling that, thing are bad in those reservoirs. If that was to be disclosed, then, KenGen shares would hit the basement
Could also explain why with all this additional electric sources, power is still expensive and the fuel powered generation stations still connected to the grid. Seven forks (btw only5 were developed) could be generating way below average
Seems like there’s a lot that we aren’t being told. All this geothermal energy and wind power is meant to replace, and not supplement the generation at the 7 forks.
Western Kenya is too gently sloping and too densely populated for any dam to be built there.
Ever.
The last time we tried it was a 34 MW power station on River Nzoia.However on establishing that they would displace over 200,000 people,the 34 MW was not worth it.
The Grand Falls dam will displace like 30,000 and it will generate between 250 to 400 MW(depending on design).
There lies the difference.
Is that displacement number current, or was that in the 70’s ? I hadn’t factored in population.
Sedimentation reduces the ability of a power station to generate power during the dry season.It has no impact on capacity to generate power in itself. The megawatts the 5 stations generate has not changed.If anything it has grown slightly as Kindaruma was upgraded a couple of years back.
I am quite sure that sedimentation does have na impact but it has nothing to do with passing through a semi arid area The area around Seven Forks is rich in vegetation due to the reserviors themselves.All the sediment comes from upcountry.
True. The high cost of power has to do with diesel powered stations.Sedimentation is a very minor factor that does not appear in our bills as the cost Kengen has been paying for hydropower has not changed in 20 years.Between 2000 and 2010 we added a lot of diesel power,no hydropower and just one geothermal power plant. Seven Forks is maxed out actually.Until they build Karura and Grand Falls,that will be the case.
They also need to expand the reserviors of Gitaru and Kamburu to reduce these incidences of low water levels during the dry season.The dependency on Masinga should stop.
Current.In Bungoma actually.
What determines the amount of power generetable (sp) by a hydro-electric plant ?
The gradient between the dam at the point where the water leaves the reservior and the power station itself.
A power station directly below the reservior works best.
Gitaru for example has a very small reservior but it gets its water from almost below it as the outlet is almost a straight line to the power station meaning water comes full force.Hence the high level of power.
Masinga on the other hand despite it having the biggest reservior is in a gently sloping area and the power station is close to the reservior hence it having to generate only 40 MW.
In some cases like Masinga,the reservior can actually raise generatable power. This applies only to Masinga. The wall if raised by a few netres can raise generating capacity to 90 MW due to increased reservior back pressure.
However notice that the reservior is s minor factor as Masinga needs a giant reservior to generate 40 MW while Gitaru and the rest do not.
Flow rate of water and height of water column above the turbines aka head.
Hydro dams are falling out of favor because they are too specific. The cost of dredging or doing a feasibility study doesn’t justify investment since our hydro plants are too tiny. That’s why the government is investing in geothermal and other renewables.
Quick question, how much are we generating from geothermal and specifically the wells developed by GDC around menengai
The dams have a mechanism set to remove the sediments. In the case of the seven folks, there is an outlet which releases water as flush so as to clean the dams. Kengen wont tell you this but its what actually happen. During rainy season they flush out water through bottom outlets found at the bottom of the dam. As a result people down stream experience unexpected and uncontrolled floods. Also the water during those time are actually brown. These flash floods happen twice every year during rainy seasons.
Menengai isn’t much, 35 MW in 3 phases. Geothermal is currently around 650MW. Plus there’s the baringo silali Wells with a potential of 3000MW but they’ll start with 300MW. The problem with geothermal is the high initial cost, so the govt has to depend on donor funding from countries like Japan. So they’ve resorted to a ppp scheme, where private companies come and develop, then kengen buys power for a period of at least 20 yrs b4 review. What we need are deeper Wells that can generate at least 500 to 1000MW.
We should put limits on the cost per kwh and minumum amount of MW per project.
I think 4.5 cents(including cost of transmission) per kwh is reasonable and cheap.Minimum MW should be between 200 MW(Homa Hills,Lake Magadi and other low potential area to 400 MW for Baringo Silali,Mount Longonot,Lake Turkana areas)
For ipps, the feed in tarrif requires a maximum of around 500MW on one site. We should also change that to exclude geothermal. I don’t see the ipps agreeing cause they are on a pioneer streak and they invest here because geothermal is more expensive than in their origin countries. For that to work we need to prolong their operating periods from 20 to 30 or 40 years and also reduce building and maintenance costs. More importantly, we need to demonopolize KPLC.
I’m hoping companies like centum don’t give up trying to sink more wells. Plus the new devki steel plant in kwale will increase the demand and force further cost effective exploration.